Imported recent work in master, minor conflict fixed in paper.mk

Only two conflicts came up in the newly added comments of 'paper.mk' in the Maneage branch. It happened because in this project we don't use 'pdflatex', but 'latex' alone.
author: Mohammad Akhlaghi <mohammad@akhlaghi.org> 2020-06-27 23:49:36 +0100
committer: Mohammad Akhlaghi <mohammad@akhlaghi.org> 2020-06-27 23:49:36 +0100
commit: 3d7d8cedfe0698e895949027906ce5ca996aad17 (patch)
tree: 108627d6dcb039ad340e75b1b14081524cc5a3df
parent: 57f922480d62a826b3e6030c81b85b412794fd4c (diff)
parent: c151eddbcc5f4208b40dc3037a8ae8adb0ff9173 (diff)
17 files changed, 2674 insertions, 2251 deletions
diff --git a/.file-metadata b/.file-metadata
index 3a4122f..9c02981 100644
--- a/.file-metadata
+++ b/.file-metadata
diff --git a/project b/project
index c117933..b6f17bb 100755
--- a/project
+++ b/project
@@ -41,6 +41,7 @@ make_targets=
 software_dir=
 clean_texdir=0
 prepare_redo=0
+all_highlevel=0
 existing_conf=0
 scriptname="./project"
 minmapsize=10000000000
@@ -77,6 +78,7 @@ operation is defined by the (mandatory) second argument:
 
   configure    - Configure project for this machine (e.g., build software).
   make         - Run the project (do analysis and build outputs).
+  shell        - Execute the project's shell for interactive testing.
 
 RECOMMENDATION: If this is the first time you are configuring this
 template, please don't use the options and let the script explain each
@@ -92,6 +94,9 @@ Project 'make' special features.
                            uploaded to servers like 'arXiv.org'.
   ./project make dist-lzip Similar to 'dist', but compress to '.tar.lz'.
   ./project make dist-zip  Similar to 'dist', but compress to '.zip'.
+  ./project make dist-software  Build a .tar.gz tarball containing all
+                                software source tarballs necessary for the
+                                project.
 
 With the options below you can modify the default behavior.
 Configure options:
@@ -105,6 +110,7 @@ Configure options:
       --clean-texdir       Remove possibly existing build-time subdirectories
                            under the project's 'tex/' directory (can happen
                            when source is from arXiv for example).
+      --all-highlevel      Build all high-level software (for development).
 
 Configure and Make options:
   -g, --group=STR          Build and run with write permissions for a group.
@@ -156,6 +162,7 @@ do
   # Main operation.
   configure)    func_operation_set $1; shift;;
   make)         func_operation_set $1; shift;;
+  shell)        func_operation_set $1; shift;;
 
 
   # Configure options:
@@ -179,6 +186,8 @@ do
   --check-config=*)      on_off_option_error --check-config;;
   --clean-texdir)        clean_texdir=1;                                                           shift;;
   --clean-texdir=*)      on_off_option_error --clean-texdir;;
+  --all-highlevel)       all_highlevel=1;                                                          shift;;
+  --all-highlevel=*)     on_off_option_error --all-highlevel;;
 
   # Configure and Make options:
   -g|--group)             group="$2";                            check_v group "$group";   shift;shift;;
@@ -271,6 +280,35 @@ fi
 
 
 
+# Error when configuration isn't run
+configuration_necessary() {
+    cat <<EOF
+
+The project is either (1) not configured on this system, or (2) the
+configuration wasn't successful.
+
+(1) If it hasn't been configured at all, use the command below to configure
+it (set a build directory and let it build its necessary software in it).
+
+      $ ./project configure
+
+(2) If it has been configured, but the configuration failed in a step, you
+can re-configure it using your previous settings with the command
+below. All successful steps will be skipped, allowing a fast completion.
+
+      $ ./project configure -e
+
+If there was a problem, please let us know by filling this online form:
+      http://savannah.nongnu.org/support/?func=additem&group=reproduce
+
+EOF
+    exit 1
+}
+
+
+
+
+
 # Run operations in controlled environment
 # ----------------------------------------
 controlled_env() {
@@ -321,11 +359,12 @@ case $operation in
         # user to have to worry about any other file that needs an
         # executable flag.
         #
-        # Basically, all the files (shell scripts) in the two
-        # `reproduce/*/bash' should need executable flags, so we are giving
-        # them executable flags by default. If any other file in your project
-        # needs such flags, add them here.
-        chmod +x reproduce/software/shell/* reproduce/analysis/bash/*
+        # Basically, all the project shell scripts need executable flags so
+        # to make sure they have them, we are activating the executable
+        # flags by default here every time './project configure' is run. If
+        # any other file in your project needs such flags, add them here.
+        chmod +x reproduce/software/shell/* reproduce/software/config/*.sh \
+              reproduce/analysis/bash/*
 
         # If the user requested, clean the TeX directory from the extra
         # (to-be-built) directories that may already be there (and will not
@@ -343,6 +382,7 @@ case $operation in
         export minmapsize=$minmapsize
         export software_dir=$software_dir
         export existing_conf=$existing_conf
+        export all_highlevel=$all_highlevel
         export reproducible_paper_group_name=$group
 
         # Run the configuration script
@@ -368,33 +408,13 @@ case $operation in
 
 
 
-    # Run the project.
+    # Batch execution of the project.
     make)
 
         # Make sure the configure script has been completed properly
         # (`configuration-done.txt' exists).
         if ! [ -f .build/software/configuration-done.txt ]; then
-            cat <<EOF
-
-The project is either (1) not configured on this system, or (2) the
-configuration wasn't successful.
-
-(1) If it hasn't been configured at all, use the command below to configure
-it (set a build directory and let it build its necessary software in it).
-
-      $ ./project configure
-
-(2) If it has been configured, but the configuration failed in a step, you
-can re-configure it using your previous settings with the command
-below. All successful steps will be skipped, allowing a fast completion.
-
-      $ ./project configure -e
-
-If there was a problem, please let us know by filling this online form:
-      http://savannah.nongnu.org/support/?func=additem&group=reproduce
-
-EOF
-            exit 1
+            configuration_necessary
         fi
 
         # Run data preparation phase (optionally build Makefiles with
@@ -425,7 +445,32 @@ EOF
         ;;
 
 
+    shell)
 
+        # Make sure the configure script has been completed properly
+        # (`configuration-done.txt' exists).
+        if ! [ -f .build/software/configuration-done.txt ]; then
+            configuration_necessary
+        fi
+
+        # Run the project's own shell without inheriting any environment
+        # from the host.
+        bdir=`.local/bin/realpath .build`
+        instdir=$bdir/software/installed
+        .local/bin/env -i \
+                       HOME=$bdir \
+                       CCACHE_DISABLE=1 \
+                       PATH=$instdir/bin \
+                       LDFLAGS=-L$instdir/lib \
+                       SHELL=$instdir/bin/bash \
+                       CPPFLAGS=-I$instdir/include \
+                       LD_LIBRARY_PATH=$instdir/lib \
+                       OMPI_MCA_plm_rsh_agent=/bin/false \
+                       PYTHONPATH=$instdir/lib/python/site-packages \
+                       PYTHONPATH3=$instdir/lib/python/site-packages \
+                       PS1="[\[\033[32m\](maneage)\[\033[00m\] \u@\h \W]$ " \
+                       $instdir/bin/bash
+        ;;
 
 
     # Operation not specified.
diff --git a/reproduce/analysis/make/initialize.mk b/reproduce/analysis/make/initialize.mk
index 489f9e3..d01cda0 100644
--- a/reproduce/analysis/make/initialize.mk
+++ b/reproduce/analysis/make/initialize.mk
@@ -243,6 +243,7 @@ clean: clean-mmap
 	rm -rf $(BDIR)/tex/macros/!(dependencies.tex|dependencies-bib.tex)
 	rm -rf $(BDIR)/!(software|tex) $(BDIR)/tex/!(macros|$(texbtopdir))
 	rm -rf $(BDIR)/tex/build/!(tikz) $(BDIR)/tex/build/tikz/*
+	rm -rf $(BDIR)/software/preparation-done.mk
 
 distclean: clean
         #  Without cleaning the Git hooks, we won't be able to easily
@@ -385,19 +386,15 @@ dist-zip: $(project-package-contents)
 # Package the software tarballs.
 dist-software:
 	curdir=$$(pwd)
+	dirname=software-$(project-commit-hash)
 	cd $(BDIR)
-	if [ -d .git ]; then
-	  dirname="software-$$(git describe --dirty --always --long)"
-	else
-	  dirname="software-NOGIT";
-	fi
 	mkdir $$dirname
 	cp -L software/tarballs/* $$dirname/
 	tar -cf $$dirname.tar $$dirname
 	gzip -f --best $$dirname.tar
 	rm -rf $$dirname
 	cd $$curdir
-	mv $(BDIR)/$$dir.tar.gz ./
+	mv $(BDIR)/$$dirname.tar.gz ./
 
 
 
diff --git a/reproduce/analysis/make/paper.mk b/reproduce/analysis/make/paper.mk
index cc43117..6d69d49 100644
--- a/reproduce/analysis/make/paper.mk
+++ b/reproduce/analysis/make/paper.mk
@@ -112,8 +112,16 @@ $(texbdir)/paper.bbl: tex/src/references.tex $(mtexdir)/dependencies-bib.tex \
           # for `biber') and then run `biber' to generate the `.bbl' file.
 	  export TEXINPUTS=$$p:
 	  cd $(texbdir);
+
+          # Note: the option '-shell-escape' is "normally disallowed for
+          # security reasons" according to the `info pdflatex' manual, but
+          # is enabled here in order to allow the use of PGFPlots. If you
+          # do not use PGFPlots, then you should remove the `-shell-escape'
+          # option for better security. See
+          # https://savannah.nongnu.org/task/?15694 for details.
 	  latex -shell-escape -halt-on-error $$p/paper.tex
 	  bibtex paper
+
           # Hack: tidy up eprint+doi style that didn't work in .bst file.
           # TODO (better): read Part 4 of
           # http://mirrors.ctan.org/info/bibtex/tamethebeast/ttb_en.pdf
@@ -150,6 +158,9 @@ paper.pdf: $(mtexdir)/project.tex paper.tex $(texbdir)/paper.bbl
 	  p=$$(pwd)
 	  export TEXINPUTS=$$p:
 	  cd $(texbdir)
+
+          # See above for a warning and brief discussion on the the
+          # pdflatex option `-shell-escape'.
 	  latex -shell-escape -halt-on-error $$p/paper.tex
 
           # Convert the DVI to PostScript, and the PostScript to PDF. The
diff --git a/reproduce/software/config/checksums.conf b/reproduce/software/config/checksums.conf
index e23df9f..2da488b 100644
--- a/reproduce/software/config/checksums.conf
+++ b/reproduce/software/config/checksums.conf
@@ -38,7 +38,7 @@ libiconv-checksum = 365dac0b34b4255a0066e8033a8b3db4bdb94b9b57a9dca17ebf2d779139
 libtool-checksum = a6eef35f3cbccf2c9e2667f44a476ebc80ab888725eb768e91a3a6c33b8c931afc46eb23efaee76c8696d3e4eed74ab1c71157bcb924f38ee912c8a90a6521a4
 libunistring-checksum = 01dcab6e05ea4c33572bf96cc0558bcffbfc0e62fc86410cef06c1597a0073d5750525fe2dee4fdb39c9bd704557fcbab864f9645958108a2e07950bc539fe54
 libxml2-checksum = cb7784ba4e72e942614e12e4f83f4ceb275f3d738b30e3b5c1f25edf8e9fa6789e854685974eed95b362049dbf6c8e7357e0327d64c681ed390534ac154e6810
-lzip-checksum = e3331bbf0166541332182a9a28c2e08f522735ef668a06dfa26055251d5142a09227d97e6ae50b38c0b8805479a307a9e55c81b120d5befad2fde44676261843
+lzip-checksum = e2e229899002072322a5bf7fb7ef37ff7cc2d0ded7d6525679ac29cec5c1534de89f76bc01e15c3d76584099957d596b9e5b32d3f9cbfc6bc8d6370fc67d7d96
 m4-checksum = a92cad4441b3fd7c033837389ca3499494523d364a5fda043d92c517051510f1758b3b837f0477f42d2258a179ab79a4993e5d1694ef2673db6d96d1faff84fe
 make-checksum = ddf0fdcb9ee1b182ef294c5da70c1275288c99bef60e63a25c0abed2ddd44aba1770be4aab1db8cac81e5f624576f2127c5d825a1824e1c7a49df4f16445526b
 metastore-checksum = b2a5fdde9de5ddc1e6c368d5da1b2e97e4fdbaa138a7be281ccb40a81dd4a9bb1849d36b2d5d3f01205079bace60441f82a7002097ff3a7037340a35b0f1574a
@@ -80,7 +80,7 @@ atlas-checksum = bf17306f09f2aa973cb776e2c9eacfb2409ad4d95d19802e1c4e0597d0a099f
 autoconf-checksum = c25e834251bfc2befe822614caf1c80d7e1314a83e7173304abc235fd15a958b8db9fbc801e8ad98328dfd6d9dbc425bfbbefec500fa268992ae7bbf4fa5bc35
 automake-checksum = 47b0120a59e3e020529a6ce750297d7de1156fd2be38db5d101e50120f11b40c28741ecd5eacf2790a9e25386713dcf7717339cfa5d7943d0dbf47c417383448
 bison-checksum = 00d2b37187b93100ec4b220ce2752d12ccf68f9d0d39b380d375d36dd8a22aa1d6e60156918f95e4493f9531c5d42d8fad38fd807307b491c1ca7ca4177823d9
-boost-checksum = 4378e20f18db9f186ac0f38ad98c522526e0fe48a8deb968c41325e3f69e733be3298505e91ea713e79a9d9e741305fa879d289f74e6276e0ec7286f03be87fc
+boost-checksum = 2844dddd3357e76909f2f3d008f686949f8b54aed29e1c650e18becd0b50701a273bb3754f1a4e56c0c056693b27c354c9ba54ddbec92599e192c2f6736fe3be
 cairo-checksum = 9eb27c4cf01c0b8b56f2e15e651f6d4e52c99d0005875546405b64f1132aed12fbf84727273f493d84056a13105e065009d89e94a8bfaf2be2649e232b82377f
 cdsclient-checksum = 2d7abf0079189b9dd19cb8919061445fd19ea9f7dfd54e8ceee26b743218cf62ab00eba0147abe82d9294223927f04b4cc3328620dfc9184a7049f8d515b29e4
 cfitsio-checksum = c0502699e266928dd25abe57730dc4b357ccc9023789fe745324ae01aa688516aceaf37321ee578f0430111d9718f0fec0dc5b54c07f935529560f00b32ce1e3
@@ -88,7 +88,7 @@ cmake-checksum = f09440681e0c414f5ca669f3aeba6666d09e0642f30a2e12c3199e7fb3da95a
 eigen-checksum = 34cf600914cce719d61511577ef9cd26fbdcb7a6fad1d0ab8396f98b887fac6a5577d3967e84a8f56225cc50de38f3b91f34f447d14312028383e32b34ea1972
 expat-checksum = 514ff2ef3c93af0b1715b7a08732db33c13a113c4c72422716a22ee26c09235deed71ec55510cee24c33bcd6b2347602bd71ce70a432d5583fb63765ff9e0e09
 fftw-checksum = ab918b742a7c7dcb56390a0a0014f517a6dff9a2e4b4591060deeb2c652bf3c6868aa74559a422a276b853289b4b701bdcbd3d4d8c08943acf29167a7be81a38
-flex-checksum = e9785f3d620a204b7d20222888917dc065c2036cae28667065bf7862dfa1b25235095a12fd04efdbd09bfd17d3452e6b9ef953a8c1137862ff671c97132a082e
+flex-checksum = b4ef58d4a1d66b213e2f59df06959decf46d26b253cdc3f51cd26e2e2b505461ef23dafa974dd2005b1f0cafa5a83fe9258baf78004b2fdae6dfc299bc17bfd1
 freetype-checksum = 02f0f4211f9cee5b5e46ebe61190482fca5b41bc26be06fcf0d2d717e9fb119229308398c420eeea476fa2511ca2d52948f1a3242efad30ca82ed0b07cd50e3a
 gdb-checksum = b4161df5adfce3eb51b3b3fc6072b2ef9f612f5e0f95b25bc57382812854836e9d1b24807c68cc8987e37e90112c6d75ffc1de3ea67a9f92858b4ce1af85c479
 ghostscript-checksum = acee64fae78771bffa19b0b2bfaba3c345b420f93ceb4fc9df5fb705f785c8ed720fde2aef53546fac6aca2f7366c64c68a6e373a71999a42dc71aadc9aa782f
@@ -104,15 +104,17 @@ libffi-checksum = 980ca30a8d76f963fca722432b1fe5af77d7a4e4d2eac5144fbc5374d4c596
 libgit2-checksum = 0879c162e2e1dc00eadfbda22cd1f9d3a95b4ec2b653c108983f37c2f695140882de4d50d7cbc04ced247125a4e9fe6df16130e1267891aecdb2411d920db5c6
 libjpeg-checksum = 74ea5af3545657d4ac03f8f7933913112cc2d982f0e379d0e5647f1acac21931468e53806297c30ebe180c7bcf84919a0ac20a4195afb03db03060d57904ef6c
 libnsl-checksum = a3c8f674357674b7ed4b26c05adde607f39be8d6dc9ff715448e1fcc5fc23d11fbb4ce85a6e493b79bdb0bb450dc3ffb1fb480715779f738d7bc016fae91621d
+libpaper-checksum = 3bf6ebb0af89931d2f72ea4a09a7fa958b2facda5f238983ec7bac39652e08614b33f0de3af74a03457b2a4203eee4950bf18a4b726e79aa64093ace6a1fb0bc
 libpng-checksum = 59e8c1059013497ae616a14c3abbe239322d3873c6ded0912403fc62fb260561768230b6ab997e2cccc3b868c09f539fd13635616b9fa0dd6279a3f63ec7e074
 libtiff-checksum = d213e5db09fd56b8977b187c5a756f60d6e3e998be172550c2892dbdb4b2a8e8c750202bc863fe27d0d1c577ab9de1710d15e9f6ed665aadbfd857525a81eea8
-libtirpc-checksum = 392f391f9fc1bd68d81dc44e4058831a64b32790b5c8c37338b0ab416fad2ae4d16389e632596734dba09780347918cc65c6f134e0c1afd09e81ec250785ed23
+libtirpc-checksum = bcb6b5c062c1301aa1246ec93ae0a5c1d221b8421126d020863517cb814b43ed038fb6c0c2faf4e68ff133b69abefe4f4d42bfc870671da6c27ca941a30b155a
 missfits-checksum = 32727f5eb30573a1cedacb8900e2536867e4815059eee32e64e3db65be9291b8a91b9f45b2c9f3cf6fc2a8cc448012ea3d502bdd9dee516008e17d5086aee795
 netpbm-checksum = 064720f8a9d0a502488e1af4daecdbf3936910996507ca6f311073a0ad842346692a148eb1ddf7b717f7b108f60500246cb4b83f4d3665f5fc285a84ae1d63d6
-openblas-checksum = 91b3074eb922453bf843158b4281cde65db9e8bbdd7590e75e9e6cdcb486157f7973f2936f327bb3eb4f1702ce0ba51ae6729d8d4baf2d986c50771e8f696df0
+openblas-checksum = 64a5f983b2f6e02cdb6e0f14433498cc5daa1ccfb49246f7a2dcd38f9982fa608f2abea069fe0e35012af8c1441c43d1f6418eaccd40795f5002fed1c36ce05d
 openmpi-checksum = 760716974cb6b25ad820184622e1ee7926bc6fda87db6b574f76792bc1ca99522e52195866c14b7cb2df5a4981efdaf9f71d2c5533cc0e8e45c2c4b3b74cbacc
 openssh-checksum = e280fa2d56f550efd37c5d2477670326261aa8b94d991f9eb17aad90e0c6c9c939efa90fe87d33260d0f709485cb05c379f0fd1bd44fc0d5190298b6398c9982
 patch-checksum = 75d4e1544484da12185418cd4a1571994398140a91ac606fa08dd067004187dad77d1413f0eb3319b3fe4df076714615c98b29df06af052bb65960fa8b0c86bf
+pcre-checksum = abac4c4f9df9e61d7d7761a9c50843882611752e1df0842a54318f358c28f5953025eba2d78997d21ee690756b56cc9f1c04a5ed591dd60654cc78ba16d9ecfb
 pixman-checksum = 1b0205dbe9d9185c68813ce577a889f3c83e83fbd9955c3a72d411c3b476e6be93fc246b5b6ef4ee17e2bb8eb6fb5559e01dff7feb6a6c4c6314f980e960d690
 python-checksum = c25a72ad792f7c1b4c2f79faebbe9608d04b04b2fe58ab804cb4732cdaa75ea93d175f5e52b38e91cb6ae0559ea6b645d802c8b6a869584e8bb9b5018367ce3d
 R-checksum = 17513e9f4dd27c61c11f7aa45227aeeeefb375bf5d4e193b471724f379a1b2da33e127cbe91aa175cbbbb048b892047e2f610280585c8159242a6c94790b07f9
diff --git a/reproduce/software/config/software_acknowledge_context.sh b/reproduce/software/config/software_acknowledge_context.sh
new file mode 100755
index 0000000..b0ede85
--- /dev/null
+++ b/reproduce/software/config/software_acknowledge_context.sh
@@ -0,0 +1,112 @@
+#!/usr/bin/env sh
+
+# Surrounding text for software acknowledgement and citation. The list of
+# names, versions and citations of the software are written by an automatic
+# script. However, through this file, users have the option to specify the
+# text surrounding those lists.
+#
+# We recommend to leave these values untouched at first, after building
+# your PDF, you can see how they surround the list of software you used in
+# your project to make a smoothly readable English text. Afterwards, please
+# feel free to modify them as you wish.
+#
+# Copyright (C) 2020 Boud Roukema <boud@cosmo.torun.pl>
+# Copyright (C) 2020 Mohammad Akhlaghi <mohammad@akhlaghi.org>
+#
+# This script is free software: you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by the
+# Free Software Foundation, either version 3 of the License, or (at your
+# option) any later version.
+#
+# This script is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
+# Public License for more details.
+#
+# A copy of the GNU General Public License is available at
+# <http://www.gnu.org/licenses/>.
+
+# WARNING:
+# In contrast to most configure files in maneage, this configure file is
+# technically a shell script, to be called by 'configure.sh', so the
+# variables defined here must follow 'shell' syntax, not 'make' syntax.
+
+# These variables will be exported to the 'configure.sh' script - so
+# descriptive, unique names should be used, to reduce the chance of
+# conflicts between identically named variables.
+
+# COMMENT:
+# Sentences have a tendancy to become very long. To avoid making the
+# variable values too long (and thus making this file hard to read), one
+# method is to break the sentence into smaller components and build the
+# full sentence gradually, similar to what we have done with 'str' in the
+# examples below. Each time, the value of 'str' is re-written by appending
+# its previous value with the rest of the sentence.
+
+# COMMENT:
+# As of 2020-06-10, the general issue of how to best cite software within
+# maneage, especially a full list of software in the Acknowledgments
+# section, remains wide open. See
+# https://savannah.nongnu.org/task/index.php?15318 for some technical
+# aspects of software citation.
+
+
+
+
+
+# Add your definitions of the LaTeX text here.
+#
+# To override a default but generate no text, use a string of non-zero
+# length such as "{}" that will have only minor effects in LaTeX.
+
+# An introduction to the software acknowledgement.
+thank_software_introduce=
+
+# The text to be used before listing C/C++ programs and libraries.
+thank_progs_libs=
+
+# The text to be used before listing Python modules.
+thank_python=
+
+# The text to be used before listing LaTeX packages.
+thank_latex=
+
+# Concluding remarks.
+thank_software_conclude=
+
+
+
+
+
+# Defaults
+# --------
+#
+# These are the default values which are only written into the variable if
+# you don't specify a value above
+if [ "x$thank_software_introduce" = "x" ]; then
+    thank_software_introduce=""
+fi
+
+if [ "x$thank_progs_libs" = "x" ]; then
+    str="This research was done with the following free software"
+    str="$str programs and libraries:"
+    thank_progs_libs="$str"
+fi
+
+if [ "x$thank_python" = "x" ]; then
+    thank_python="Within Python, the following modules were used:"
+fi
+
+if [ "x$thank_latex" = "x" ]; then
+    str="The \LaTeX{} source of the paper was compiled to make the"
+    str="$str PDF using the following packages:"
+    thank_latex="$str"
+fi
+
+if [ "x${thank_software_conclude}" = "x" ]; then
+    str="We are very grateful to all their creators for freely "
+    str="$str providing this necessary infrastructure. This research "
+    str="$str (and many other projects) would not be possible without "
+    str="$str them."
+    thank_software_conclude="$str"
+fi
diff --git a/reproduce/software/config/urls.conf b/reproduce/software/config/urls.conf
new file mode 100644
index 0000000..dc5a9d8
--- /dev/null
+++ b/reproduce/software/config/urls.conf
@@ -0,0 +1,159 @@
+# Optional URLs of software to use for downloading their source
+#
+# If un-commented the URLs of this file will be used. Otherwise default
+# servers (primarily on 'zenodo.org') will be checked for the tarball.
+#
+# Copyright (C) 2020 Mohammad Akhlaghi <mohammad@akhlaghi.org>
+# Copyright (C) 2020 Raul Infante-Sainz <infantesainz@gmail.com>
+#
+# Copying and distribution of this file, with or without modification, are
+# permitted in any medium without royalty provided the copyright notice and
+# this notice are preserved.  This file is offered as-is, without any
+# warranty.
+
+
+
+
+
+# Basic/low-level programs and libraires (installed in any case)
+# --------------------------------------------------------------
+#bash-url = http://akhlaghi.org/maneage-software
+#binutils-url = http://ftp.gnu.org/gnu/binutils
+#bzip2-url = http://akhlaghi.org/maneage-software
+#cert-url = http://akhlaghi.org/maneage-software
+#coreutils-url = http://ftp.gnu.org/gnu/coreutils
+#curl-url = https://curl.haxx.se/download
+#dash-url = http://akhlaghi.org/maneage-software
+#diffutils-url = http://ftp.gnu.org/gnu/diffutils
+#file-url = ftp://ftp.astron.com/pub/file
+#findutils-url = http://ftp.gnu.org/gnu/findutils
+#flock-url = http://akhlaghi.org/src
+#gawk-url = http://ftp.gnu.org/gnu/gawk
+#gcc-url = http://ftp.gnu.org/gnu/gcc/gcc-$(gcc-version)
+#gettext-url = https://ftp.gnu.org/gnu/gettext
+#git-url = http://mirrors.edge.kernel.org/pub/software/scm/git
+#gmp-url = https://gmplib.org/download/gmp
+#grep-url = http://ftp.gnu.org/gnu/grep
+#gzip-url = http://akhlaghi.org/src
+#isl-url = ftp://gcc.gnu.org/pub/gcc/infrastructure
+#libbsd-url = http://libbsd.freedesktop.org/releases
+#libiconv-url = https://ftp.gnu.org/pub/gnu/libiconv
+#libtool-url = http://ftp.gnu.org/gnu/libtool
+#libunistring-url = http://ftp.gnu.org/gnu/libunistring
+#libxml2-url = ftp://xmlsoft.org/libxml2
+#lzip-url = http://akhlaghi.org/src
+#m4-url = http://akhlaghi.org/maneage-software
+#make-url = http://akhlaghi.org/src
+#metastore-url = http://akhlaghi.org/maneage-software
+#mpc-url = http://ftp.gnu.org/gnu/mpc
+#mpfr-url = http://www.mpfr.org/mpfr-current
+#ncurses-url = http://ftp.gnu.org/gnu/ncurses
+#openssl-url = http://www.openssl.org/source
+#patchelf-url = http://nixos.org/releases/patchelf/patchelf-$(patchelf-version)
+#perl-url = $(shell echo https://www.cpan.org/src/$$(echo $(perl-version) | sed -e's/\./ /g' | awk '{printf("%d.0", $$1)}'))
+#pkgconfig-url = http://pkg-config.freedesktop.org/releases
+#readline-url = http://ftp.gnu.org/gnu/readline
+#sed-url = http://ftp.gnu.org/gnu/sed
+#tar-url = http://ftp.gnu.org/gnu/tar
+#texinfo-url = http://ftp.gnu.org/gnu/texinfo
+#unzip-url = $(shell echo ftp://ftp.info-zip.org/pub/infozip/src/unzip$$(echo $(unzip-version) | sed -e's/\.//').tgz)
+#wget-url = http://ftp.gnu.org/gnu/wget
+#which-url = http://ftp.gnu.org/gnu/which
+#xz-url = http://tukaani.org/xz
+#zip-url = $(shell echo ftp://ftp.info-zip.org/pub/infozip/src/zip$$(echo $(zip-version) | sed -e's/\.//').tgz)
+#zlib-url = http://www.zlib.net
+
+
+
+
+
+# Optional/high-level programs and libraries
+# ------------------------------------------
+#
+# These are programs and libraries that are optional, The ones in
+# `reproduce/software/config/TARGETS.conf' will be built as
+# part of a project. To specify a software there, just remove the
+# `-url' suffix from the list below.
+#apachelog4cxx-url = http://akhlaghi.org/maneage-software
+#apr-url = https://www-us.apache.org/dist/apr
+#apr-util-url = https://www-us.apache.org/dist/apr
+#astrometrynet-url = http://astrometry.net/downloads
+#atlas-url = https://sourceforge.net/projects/math-atlas/files/Stable/$(atlas-version)/atlas$(atlas-version).tar.bz2/download
+#autoconf-url = http://akhlaghi.org/maneage-software
+#automake-url = http://ftp.gnu.org/gnu/automake
+#bison-url = http://ftp.gnu.org/gnu/bison
+#boost-url = $(shell vstr=$$(echo $(boost-version) | sed -e's/\./_/g'); echo https://dl.bintray.com/boostorg/release/$(boost-version)/source)
+#cairo-url = https://www.cairographics.org/releases
+#cdsclient-url = http://cdsarc.u-strasbg.fr/ftp/pub/sw
+#cfitsio-url = https://heasarc.gsfc.nasa.gov/FTP/software/fitsio/c
+#cmake-url = $(shell majv=$$(echo $(cmake-version) | sed -e's/\./ /' | awk '{printf("%d.%d", $$1, $$2)}'); echo https://cmake.org/files/v$$majv/cmake-$(cmake-version).tar.gz)
+#eigen-url = http://bitbucket.org/eigen/eigen/get/$(eigen-version).tar.gz
+#expat-url = $(shell vstr=$$(echo $(expat-version) | sed -e's/\./_/g'); echo https://github.com/libexpat/libexpat/releases/download/R_$$vstr/expat-$(expat-version).tar.lz)
+#fftw-url = ftp://ftp.fftw.org/pub/fftw
+#flex-url = https://github.com/westes/flex/files/981163
+#freetype-url = https://download.savannah.gnu.org/releases/freetype
+#gdb-url = http://ftp.gnu.org/gnu/gdb
+#ghostscript-url = $(shell v=$$(echo $(ghostscript-version) | sed -e's/\.//'); echo https://github.com/ArtifexSoftware/ghostpdl-downloads/releases/download/gs$$v)
+#gnuastro-url = http://ftp.gnu.org/gnu/gnuastro
+#gsl-url = http://ftp.gnu.org/gnu/gsl
+#hdf5-url = $(shell majorver=$$(echo $(hdf5-version) | sed -e 's/\./ /g' | awk '{printf("%d.%d", $$1, $$2)}'); echo https://support.hdfgroup.org/ftp/HDF5/releases/hdf5-$$majorver/hdf5-$(hdf5-version)/src)
+#healpix-url = http://akhlaghi.org/maneage-software
+#help2man-url = http://ftp.gnu.org/gnu/help2man
+#imagemagick-url = http://akhlaghi.org/maneage-software
+#imfit-url = http://www.mpe.mpg.de/~erwin/resources/imfit
+#lapack-url = http://www.netlib.org/lapack
+#libffi-url = ftp://sourceware.org/pub/libffi
+#libgit2-url = https://github.com/libgit2/libgit2/archive
+#libjpeg-url = http://ijg.org/files
+#libnsl-url = http://akhlaghi.org/maneage-software
+#ibpaper-url=http://ftp.debian.org/debian/pool/main/libp/libpaper/
+#libpng-url = https://download.sourceforge.net/libpng
+#libtiff-url = https://download.osgeo.org/libtiff
+#libtirpc-url = https://downloads.sourceforge.net/libtirpc
+#minizip-url =
+#missfits-url = https://www.astromatic.net/download/missfits
+#netpbm-url = http://akhlaghi.org/maneage-software
+#openblas-url = https://github.com/xianyi/OpenBLAS/archive
+#openmpi-url = $(shell majorver=$$(echo $(openmpi-version) | sed -e 's/\./ /g' | awk '{printf("%d.%d", $$1, $$2)}'); echo https://download.open-mpi.org/release/open-mpi/v$$majorver)
+#openssh-url = https://artfiles.org/openbsd/OpenSSH/portable
+#patch-url = http://ftp.gnu.org/gnu/patch
+#pixman-url = https://www.cairographics.org/releases
+#python-url = https://www.python.org/ftp/python/$(python-version)
+#R-url = $(shell majver=$$(echo $(R-version) | sed -e's/\./ /g' | awk '{print $$1}'); echo https://cran.r-project.org/src/base/R-$$majver)
+#rpcsvc-proto-url = https://github.com/thkukuk/rpcsvc-proto/releases/download
+#scamp-url = http://akhlaghi.org/maneage-software
+#scons-url = https://sourceforge.net/projects/scons/files/scons/$(scons-version)/scons-$(scons-version).tar.gz/download
+#sextractor-url = http://akhlaghi.org/maneage-software
+#swarp-url = https://www.astromatic.net/download/swarp
+#swig-url = https://sourceforge.net/projects/swig/files/swig/swig-$(swig-version)
+#tides-url = http://akhlaghi.org/maneage-software
+#valgrind-url = https://sourceware.org/pub/valgrind
+#wcslib-url = ftp://ftp.atnf.csiro.au/pub/software/wcslib
+#xlsxio-url = https://github.com/brechtsanders/xlsxio/archive
+#yaml-url = pyyaml.org/download/libyaml
+
+
+
+
+
+# Python packages
+# ---------------
+#
+# Similar to optional programs and libraries above.
+#
+# IMPORTANT: Python packages are usually distributed on servers like
+# 'https://pypi.org'. You can search for your package here and add the link
+# to the tarball here for your desired software. The links in PyPi don't
+# contain the names of the software, but only have hashes. So we aren't
+# including them by default here. But adding them is trivial for a certain
+# version. For example if you search "Numpy" and click on the "Download
+# files" menu, you can download the source '.zip' file. For version 1.18.5,
+# (with full filename of 'numpy-1.18.5.zip') the link will be like this.
+#
+#  numpy-url = https://files.pythonhosted.org/packages/01/1b/d3ddcabd5817be02df0e6ee20d64f77ff6d0d97f83b77f65e98c8a651981/numpy-1.18.5.zip
+#
+# Hence, if the version changes, the checksum, and its two top host
+# directories also change. This is why we aren't putting any URL here by
+# default, if you need to add one, simply follow the numpy example above.
+# But be sure to send us a link to the tarball so we upload it to Maneage's
+# backup servers.
diff --git a/reproduce/software/config/versions.conf b/reproduce/software/config/versions.conf
index 1a4172a..b395e0f 100644
--- a/reproduce/software/config/versions.conf
+++ b/reproduce/software/config/versions.conf
@@ -14,6 +14,8 @@
 
 # Basic/low-level programs and libraires (installed in any case)
 # --------------------------------------------------------------
+#
+# CLASS:BASIC (important identifier, don't modify this line)
 bash-version = 5.0.11
 binutils-version = 2.32
 coreutils-version = 8.31
@@ -22,6 +24,7 @@ dash-version = 0.5.10.2
 diffutils-version = 3.7
 file-version = 5.36
 findutils-version = 4.7.0
+flock-version = 0.2.3
 gawk-version = 5.0.1
 gcc-version = 9.2.0
 gettext-version = 0.20.2
@@ -35,8 +38,8 @@ libiconv-version = 1.16
 libtool-version = 2.4.6
 libunistring-version = 0.9.10
 libxml2-version = 2.9.9
-lzip-version = 1.20
-m4-version = 1.4.18
+lzip-version = 1.22-rc2
+m4-version = 1.4.18-patched
 make-version = 4.3
 metastore-version = 1.1.2-23-fa9170b
 mpc-version = 1.1.0
@@ -56,6 +59,14 @@ xz-version = 5.2.4
 zip-version = 3.0
 zlib-version = 1.2.11
 
+# Version-dependent build
+# -----------------------
+#
+# When updating the version of these programs/libraries, please look into
+# the build rule first: In one way or another, the version string becomes
+# necessary during their build and must be accounted for.
+bzip2-version = 1.0.6
+
 
 
 
@@ -67,6 +78,8 @@ zlib-version = 1.2.11
 # `reproduce/software/config/TARGETS.conf' will be built as
 # part of a project. To specify a software there, just remove the
 # `-version' suffix from the list below.
+#
+# CLASS:HIGHLEVEL (important identifier, don't modify this line.)
 apachelog4cxx-version = 0.10.0-603-014954db
 apr-version = 1.7.0
 apr-util-version = 1.6.1
@@ -75,7 +88,7 @@ atlas-version = 3.10.3
 autoconf-version = 2.69.200-babc
 automake-version = 1.16.1
 bison-version = 3.4.2
-boost-version = 1.71.0
+boost-version = 1.73.0
 cairo-version = 1.16.0
 cdsclient-version = 3.84
 cfitsio-version = 3.47
@@ -83,8 +96,7 @@ cmake-version = 3.17.0
 eigen-version = 3.3.7
 expat-version = 2.2.9
 fftw-version = 3.3.8
-flex-version = 2.6.4
-flock-version = 0.2.3
+flex-version = 2.6.4-91-ga631f5d
 freetype-version = 2.9
 gdb-version = 8.3
 ghostscript-version = 9.50
@@ -98,14 +110,16 @@ imfit-version = 1.6.1
 libffi-version = 3.2.1
 libjpeg-version = v9b
 libnsl-version = 1.2.0-4a062cf
+libpaper-version = 1.1.28
 libpng-version = 1.6.37
 libtiff-version = 4.0.10
-libtirpc-version = 1.1.4
+libtirpc-version = 1.2.6
 missfits-version = 2.8.0
-openblas-version = 0.3.5
+openblas-version = 0.3.10
 openmpi-version = 4.0.1
 openssh-version = 8.0p1
 patch-version = 2.7.6
+pcre-version = 8.44
 pixman-version = 0.38.0
 python-version = 3.7.4
 R-version = 3.6.2
@@ -119,6 +133,29 @@ tides-version = 2.0
 xlsxio-version = 0.2.21
 yaml-version = 0.2.2
 
+# Version-dependent build
+# -----------------------
+lapack-version = 3.8.0
+libgit2-version = 0.28.2
+wcslib-version = 6.4
+
+# Netpbm's questions in the configure steps maybe change with different or
+# new versions.
+netpbm-version = 10.86.99
+
+# Minizip is installed with the same `zlib' tarball, and they have the same
+# version.
+minizip-version = $(zlib-version)
+
+# From version 1.2 OpenSSL may not need a manual addition, as described in
+# its comments and `https://savannah.nongnu.org/bugs/?58263'. If it doesn't
+# cause problems, put it back in the list of "Basic/low-level" tools.
+openssl-version = 1.1.1a
+
+# Version 3.15.0 needs two patches, please check if they are necessary on
+# any future release.
+valgrind-version = 3.15.0
+
 
 
 
@@ -131,6 +168,8 @@ yaml-version = 0.2.2
 # IMPORTANT: If you intend to change the version of any of the Python
 # modules/libraries below, please fix the hash strings of the respective
 # URL in `reproduce/software/make/python.mk'.
+#
+# CLASS:PYTHON (important identifier, don't modify this line.)
 asn1crypto-version = 0.24.0
 asteval-version = 0.9.16
 astropy-version = 4.0
@@ -151,7 +190,6 @@ flake8-version = 3.7.8
 future-version = 0.18.1
 galsim-version = 2.2.1
 h5py-version = 2.9.0
-healpy-version = installed-with-healpix
 html5lib-version = 1.0.1
 idna-version = 2.8
 jeepney-version = 0.4
@@ -184,42 +222,9 @@ soupsieve-version = 1.8
 sympy-version = 1.4
 uncertainties-version = 3.1.2
 urllib3-version = 1.24.1
-virtualenv-version = 16.4.0
 webencodings-version = 0.5.1
 
-
-
-
-
-# Special programs and libraries
-# ------------------------------
-#
-# When updating the version of these libraries, please look into the build
-# rule first: In one way or another, the version string becomes necessary
-# during their build and must be accounted for.
+# Special Python modules:
 #
-# Special notes:
-#   - `netpbm' questions in the configure steps maybe change with different
-#   or new versions.
-
-# Basic/low-level
-bzip2-version = 1.0.6
-
-# Optional/high-level
-lapack-version = 3.8.0
-libgit2-version = 0.28.2
-netpbm-version = 10.86.99
-wcslib-version = 6.4
-
-# Minizip is installed with the same `zlib' tarball, and they have the same
-# version.
-minizip-version = $(zlib-version)
-
-# From version 1.2 OpenSSL may not need a manual addition, as described in
-# its comments and `https://savannah.nongnu.org/bugs/?58263'. If it doesn't
-# cause problems, put it back in the list of "Basic/low-level" tools.
-openssl-version = 1.1.1a
-
-# Version 3.15.0 needs two patches, please check if they are necessary on
-# any future release.
-valgrind-version = 3.15.0
+# Healpy: When any Python module is requested, healpix will also build its
+#         Python module Healpy.
diff --git a/reproduce/software/make/atlas-multiple.mk b/reproduce/software/make/atlas-multiple.mk
index 9bd26b1..9bd26b1 100755..100644
--- a/reproduce/software/make/atlas-multiple.mk
+++ b/reproduce/software/make/atlas-multiple.mk
diff --git a/reproduce/software/make/atlas-single.mk b/reproduce/software/make/atlas-single.mk
index 29373e0..29373e0 100755..100644
--- a/reproduce/software/make/atlas-single.mk
+++ b/reproduce/software/make/atlas-single.mk
diff --git a/reproduce/software/make/basic.mk b/reproduce/software/make/basic.mk
index 82bc42d..94bb5d4 100644
--- a/reproduce/software/make/basic.mk
+++ b/reproduce/software/make/basic.mk
@@ -5,13 +5,19 @@
 #                      !!!!! IMPORTANT NOTES !!!!!
 #
 # This Makefile will be run by the initial `./project configure' script. It
-# is not included into the project after that.
+# is not included into the project afterwards.
 #
-# This Makefile builds very low-level and basic tools like GNU Tar, GNU
-# Bash, GNU Make, GCC and etc. Therefore this is the only Makefile in the
-# project where you CANNOT assume that GNU Bash or GNU Make are used. After
-# this Makefile (where GNU Bash and GNU Make are built), other Makefiles
-# can safely assume the fixed version of all these software.
+# This Makefile builds low-level and basic tools that are necessary in any
+# project like like GNU Tar, GNU Bash, GNU Make, GCC and etc. But before
+# control reaches here, the 'configure.sh' script has already built the
+# extremely low-level tools: Lzip (a compressing program), GNU Make (to be
+# able to run this Makefile with a fixed version), Dash (a minimalist
+# POSIX-compatible shell) and Flock (to allow locking files, and
+# serializing when necessary: downloading during the software building
+# phase). Thanks to GNU Make and Dash, we can assume a fixed structure in
+# this Makefile. However, the 'PATH's in this Makefile still include the
+# host's paths because we will be using the hosts tools (gradually
+# decreasing) to build our own tools.
 #
 # ------------------------------------------------------------------------
 #
@@ -31,13 +37,17 @@
 # You should have received a copy of the GNU General Public License
 # along with this Makefile.  If not, see <http://www.gnu.org/licenses/>.
 
-
 # Top level environment
 include reproduce/software/config/LOCAL.conf
 include reproduce/software/make/build-rules.mk
 include reproduce/software/config/versions.conf
 include reproduce/software/config/checksums.conf
 
+# The optional URLs of software. Note that these may need the software
+# version, so it is important that they be loaded after 'versions.conf'.
+include reproduce/software/config/urls.conf
+
+# Basic directories
 lockdir = $(BDIR)/locks
 tdir    = $(BDIR)/software/tarballs
 ddir    = $(BDIR)/software/build-tmp
@@ -46,31 +56,34 @@ ibdir   = $(BDIR)/software/installed/bin
 ildir   = $(BDIR)/software/installed/lib
 ibidir  = $(BDIR)/software/installed/version-info/proglib
 
-# We'll need the system's PATH for making links to low-level programs we
-# won't be building ourselves.
-syspath := $(PATH)
+# Ultimate Makefile target.
+targets-proglib = low-level-links gcc-$(gcc-version)
+all: $(foreach p, $(targets-proglib), $(ibidir)/$(p))
 
+# Define the shell environment
+# ----------------------------
+#
+# We build GNU Bash here in 'basic.mk'. So here we must must assume DASH
+# shell that was built before calling this Makefile:
+# http://gondor.apana.org.au/~herbert/dash. DASH is a minimalist POSIX
+# shell, so it doesn't have startup options like '--noprofile --norc'. But
+# from its manual, to load startup files, Dash actually requires that it be
+# called with a '-' before it (for example '-dash'), so it shouldn't be
+# loading any startup files if it was interpretted properly.
+#
 # As we build more programs, we want to use this project's built programs
-# and libraries, not the host's.
+# and libraries, not the host's, so in all PATH-related environments, our
+# own build-directory comes first.
 .ONESHELL:
+.SHELLFLAGS := -e -c
 export CCACHE_DISABLE := 1
+export SHELL := $(ibdir)/dash
 export PATH := $(ibdir):$(PATH)
 export PKG_CONFIG_PATH := $(ildir)/pkgconfig
 export PKG_CONFIG_LIBDIR := $(ildir)/pkgconfig
 export CPPFLAGS := -I$(idir)/include $(CPPFLAGS)
 export LDFLAGS := $(rpath_command) -L$(ildir) $(LDFLAGS)
 
-# Note that we build GNU Bash here in 'basic.mk'. So we can't assume Bash
-# in this Makefile and use the DASH shell that was before calling this
-# Makefile: http://gondor.apana.org.au/~herbert/dash. Dash is a minimalist
-# POSIX shell, so it doesn't have startup options like '--noprofile
-# --norc'. But from its manual, to load startup files, Dash actually
-# requires that it be called with a '-' before it (for example '-dash'), so
-# it shouldn't be loading any startup files if it was interpretted
-# properly.
-.SHELLFLAGS := -e -c
-export SHELL := $(ibdir)/dash
-
 # This is the "basic" tools where we are relying on the host operating
 # system, but are slowly populating our basic software envirnoment. To run
 # (system or template) programs, `LD_LIBRARY_PATH' is necessary, so here,
@@ -86,202 +99,29 @@ export LD_LIBRARY_PATH := $(shell echo $(LD_LIBRARY_PATH):$(ildir) \
 # causes crashs (see bug #56682). So we'll just give it no value at all.
 export DYLD_LIBRARY_PATH :=
 
-# Recipe startup script.
-export PROJECT_STATUS := configure_basic
-export BASH_ENV := $(shell pwd)/reproduce/software/shell/bashrc.sh
-
-# Define the top-level basic programs (that don't depend on any other).
-top-level-programs = low-level-links gcc
-all: $(foreach p, $(top-level-programs), $(ibidir)/$(p))
-
-# Servers to use as backup, later this should go in a file that is not
-# under version control (the actual server that the tarbal comes from is
-# irrelevant).
-backupservers := $(shell awk '!/^#/{printf "%s ", $$1}' \
-                         reproduce/software/config/servers-backup.conf)
-
-
-
-
-
-
-# Tarballs
-# --------
-#
-# Prepare tarballs. Difference with that in `high-level.mk': `.ONESHELL' is
-# not recognized by some versions of Make (even older GNU Makes). So we'll
-# have to make sure the recipe doesn't break into multiple shell calls (so
-# we can preserve the variables).
-#
-# Software with main webpage at our backup repository
-# (http://akhlaghi.org/maneage-software): As of our latest check their
-# major release tarballs either crash or don't build on some systems (for
-# example Make or Gzip), or they don't exist (for example Bzip2). So we are
-# building them from their Git history (which builds properly) or host them
-# directly.
+# Servers to use as backup. Maneage already has some fixed servers that can
+# be used to download software tarballs. They are in a configuation
+# file. But we give precedence to the "user" backup servers.
 #
-# In the first case, we used their Git repo and bootstrapped them (just
-# like Gnuastro) and built the most recent tarball off of that. In the case
-# of Bzip2: its webpage has expired and doesn't host the data any more. It
-# is available on the link below (archive.org):
+# One important "user" server (which the user doesn't actually give, but is
+# found at configuration time in 'configure.sh') is Zenodo (see the
+# description in 'configure.sh' for more on why this depends on
+# configuration time).
 #
-# https://web.archive.org/web/20180624184806/http://www.bzip.org/1.0.6/bzip2-1.0.6.tar.gz
-#
-# However, downloading from this link is slow (because its just a link). So
-# its easier to just keep a with the others.
-$(lockdir): | $(BDIR); mkdir $@
+# Afer putting everything together, we use the first server as the
+# reference for all software if their '-url' variable isn't defined (in
+# 'reproduce/software/config/urls.conf').
 downloadwrapper = ./reproduce/analysis/bash/download-multi-try
-tarballs = $(foreach t, bash-$(bash-version).tar.lz \
-                        binutils-$(binutils-version).tar.lz \
-                        bzip2-$(bzip2-version).tar.gz \
-                        cert.pem \
-                        coreutils-$(coreutils-version).tar.xz \
-                        curl-$(curl-version).tar.gz \
-                        diffutils-$(diffutils-version).tar.xz \
-                        file-$(file-version).tar.gz \
-                        findutils-$(findutils-version).tar.xz \
-                        gawk-$(gawk-version).tar.lz \
-                        gcc-$(gcc-version).tar.xz \
-                        gettext-$(gettext-version).tar.xz \
-                        git-$(git-version).tar.xz \
-                        gmp-$(gmp-version).tar.lz \
-                        grep-$(grep-version).tar.xz \
-                        gzip-$(gzip-version).tar.lz \
-                        isl-$(isl-version).tar.bz2 \
-                        libbsd-$(libbsd-version).tar.xz	\
-                        libiconv-$(libiconv-version).tar.gz \
-                        libtool-$(libtool-version).tar.xz \
-                        libunistring-$(libunistring-version).tar.xz \
-                        libxml2-$(libxml2-version).tar.gz \
-                        m4-$(m4-version).tar.gz \
-                        metastore-$(metastore-version).tar.gz \
-                        mpfr-$(mpfr-version).tar.xz \
-                        mpc-$(mpc-version).tar.gz \
-                        ncurses-$(ncurses-version).tar.gz \
-                        openssl-$(openssl-version).tar.gz \
-                        patchelf-$(patchelf-version).tar.gz \
-                        perl-$(perl-version).tar.gz \
-                        pkg-config-$(pkgconfig-version).tar.gz \
-                        readline-$(readline-version).tar.gz \
-                        sed-$(sed-version).tar.xz \
-                        tar-$(tar-version).tar.gz \
-                        texinfo-$(texinfo-version).tar.xz \
-                        unzip-$(unzip-version).tar.gz \
-                        wget-$(wget-version).tar.lz \
-                        which-$(which-version).tar.gz \
-                        xz-$(xz-version).tar.gz \
-                        zip-$(zip-version).tar.gz \
-                        zlib-$(zlib-version).tar.gz \
-                      , $(tdir)/$(t) )
-$(tarballs): $(tdir)/%: | $(lockdir)
-
-        # Remove the version numbers and suffix from the tarball name so we
-        # can search more easily only with the program name. This requires
-        # the first character of the version to be a digit: packages such
-        # as `foo' and `foo-3' will not be distinguished, but `foo' and
-        # `foo2' will be distinguished.
-	@n=$$(echo $* | sed -e's/-[0-9]/ /' -e's/\./ /g' \
-	             | awk '{print $$1}' )
-
-	mergenames=1; \
-	if   [ $$n = bash      ]; then c=$(bash-checksum); w=http://akhlaghi.org/maneage-software
-	elif [ $$n = binutils  ]; then c=$(binutils-checksum); w=http://ftp.gnu.org/gnu/binutils
-	elif [ $$n = bzip2     ]; then c=$(bzip2-checksum); w=http://akhlaghi.org/maneage-software
-	elif [ $$n = cert      ]; then c=$(cert-checksum); w=http://akhlaghi.org/maneage-software
-	elif [ $$n = coreutils ]; then c=$(coreutils-checksum); w=http://ftp.gnu.org/gnu/coreutils
-	elif [ $$n = curl      ]; then c=$(curl-checksum); w=https://curl.haxx.se/download
-	elif [ $$n = diffutils ]; then c=$(diffutils-checksum); w=http://ftp.gnu.org/gnu/diffutils
-	elif [ $$n = file      ]; then c=$(file-checksum); w=ftp://ftp.astron.com/pub/file
-	elif [ $$n = findutils ]; then c=$(findutils-checksum); w=http://ftp.gnu.org/gnu/findutils
-	elif [ $$n = gawk      ]; then c=$(gawk-checksum); w=http://ftp.gnu.org/gnu/gawk
-	elif [ $$n = gcc       ]; then c=$(gcc-checksum); w=http://ftp.gnu.org/gnu/gcc/gcc-$(gcc-version)
-	elif [ $$n = gettext   ]; then c=$(gettext-checksum); w=https://ftp.gnu.org/gnu/gettext
-	elif [ $$n = git       ]; then c=$(git-checksum); w=http://mirrors.edge.kernel.org/pub/software/scm/git
-	elif [ $$n = gmp       ]; then c=$(gmp-checksum); w=https://gmplib.org/download/gmp
-	elif [ $$n = grep      ]; then c=$(grep-checksum); w=http://ftp.gnu.org/gnu/grep
-	elif [ $$n = gzip      ]; then c=$(gzip-checksum); w=http://akhlaghi.org/src
-	elif [ $$n = isl       ]; then c=$(isl-checksum); w=ftp://gcc.gnu.org/pub/gcc/infrastructure
-	elif [ $$n = libbsd    ]; then c=$(libbsd-checksum); w=http://libbsd.freedesktop.org/releases
-	elif [ $$n = libiconv  ]; then c=$(libiconv-checksum); w=https://ftp.gnu.org/pub/gnu/libiconv
-	elif [ $$n = libtool   ]; then c=$(libtool-checksum); w=http://ftp.gnu.org/gnu/libtool
-	elif [ $$n = libunistring ]; then c=$(libunistring-checksum); w=http://ftp.gnu.org/gnu/libunistring
-	elif [ $$n = libxml2   ]; then c=$(libxml2-checksum); w=ftp://xmlsoft.org/libxml2
-	elif [ $$n = m4        ]; then
-	  mergenames=0
-	  c=$(m4-checksum)
-	  w=http://akhlaghi.org/maneage-software/m4-1.4.18-patched.tar.gz
-	elif [ $$n = metastore ]; then c=$(metastore-checksum); w=http://akhlaghi.org/maneage-software
-	elif [ $$n = mpc       ]; then c=$(mpc-checksum); w=http://ftp.gnu.org/gnu/mpc
-	elif [ $$n = mpfr      ]; then c=$(mpfr-checksum); w=http://www.mpfr.org/mpfr-current
-	elif [ $$n = ncurses   ]; then c=$(ncurses-checksum); w=http://ftp.gnu.org/gnu/ncurses
-	elif [ $$n = openssl   ]; then c=$(openssl-checksum); w=http://www.openssl.org/source
-	elif [ $$n = patchelf  ]; then c=$(patchelf-checksum); w=http://nixos.org/releases/patchelf/patchelf-$(patchelf-version)
-	elif [ $$n = perl      ]; then
-	  c=$(perl-checksum)
-	  v=$$(echo $(perl-version) | sed -e's/\./ /g' | awk '{printf("%d.0", $$1)}')
-	  w=https://www.cpan.org/src/$$v
-	elif [ $$n = pkg-config ]; then c=$(pkgconfig-checksum); w=http://pkg-config.freedesktop.org/releases
-	elif [ $$n = readline  ]; then c=$(readline-checksum); w=http://ftp.gnu.org/gnu/readline
-	elif [ $$n = sed       ]; then c=$(sed-checksum); w=http://ftp.gnu.org/gnu/sed
-	elif [ $$n = tar       ]; then c=$(tar-checksum); w=http://ftp.gnu.org/gnu/tar
-	elif [ $$n = texinfo   ]; then c=$(texinfo-checksum); w=http://ftp.gnu.org/gnu/texinfo
-	elif [ $$n = unzip     ]; then
-	  c=$(unzip-checksum)
-	  mergenames=0; v=$$(echo $(unzip-version) | sed -e's/\.//')
-	  w=ftp://ftp.info-zip.org/pub/infozip/src/unzip$$v.tgz
-	elif [ $$n = wget      ]; then c=$(wget-checksum); w=http://ftp.gnu.org/gnu/wget
-	elif [ $$n = which     ]; then c=$(which-checksum); w=http://ftp.gnu.org/gnu/which
-	elif [ $$n = xz        ]; then c=$(xz-checksum); w=http://tukaani.org/xz
-	elif [ $$n = zip       ]; then
-	  c=$(zip-checksum)
-	  mergenames=0; v=$$(echo $(zip-version) | sed -e's/\.//')
-	  w=ftp://ftp.info-zip.org/pub/infozip/src/zip$$v.tgz
-	elif [ $$n = zlib      ]; then c=$(zlib-checksum); w=http://www.zlib.net
-	else
-	  echo; echo; echo
-	  echo "'$$n' not recognized as a software tarball name to download."
-	  echo; echo; echo
-	  exit 1
-	fi
+maneage_backup_urls := $(shell awk '!/^#/{printf "%s ", $$1}' \
+                               reproduce/software/config/servers-backup.conf)
+backupservers_all = $(user_backup_urls) $(maneage_backup_urls)
+topbackupserver = $(word 1, $(backupservers_all))
+backupservers = $(filter-out $(topbackupserver),$(backupservers_all))
+
 
-        # Download the raw tarball, using an '.unchecked' suffix to specify
-        # that it is not yet fully checked and usable. But first, since the
-        # download may be interrupted in a previous build and an incomplete
-        # '.unchecked' file may remain, we'll remove any possibly existing
-        # uncheked file.
-	rm -f "$@.unchecked"
-	if [ -f $(DEPENDENCIES-DIR)/$* ]; then
-	  cp $(DEPENDENCIES-DIR)/$* "$@.unchecked"
-	else
-	  if [ $$mergenames = 1 ]; then  tarballurl=$$w/"$*"
-	  else                           tarballurl=$$w
-	  fi
 
-	  echo "Downloading $$tarballurl"
-	  if [ -f $(ibdir)/wget ]; then
-	    downloader="wget --no-use-server-timestamps -O"
-	  else
-	    downloader="$(DOWNLOADER)"
-	  fi
 
-	  touch $(lockdir)/download
-	  $(downloadwrapper) "$$downloader" $(lockdir)/download \
-	                     $$tarballurl "$@.unchecked" "$(backupservers)"
-	fi
 
-        # Make sure the file's Checksum is correct.
-	if type sha512sum > /dev/null 2>/dev/null; then
-	  checksum=$$(sha512sum "$@.unchecked" | awk '{print $$1}')
-	  if [ x"$$checksum" = x"$$c" ]; then
-	    mv "$@.unchecked" "$@"
-	  else
-	    echo "ERROR: Non-matching checksum for '$*'."
-	    echo "Checksum should be: $$c"
-	    echo "Checksum is:        $$checksum"
-	    exit 1
-	  fi
-	else mv "$@.unchecked" "$@"
-	fi
 
 
 
@@ -301,6 +141,10 @@ $(tarballs): $(tdir)/%: | $(lockdir)
 # purpose here, it is very annoying and can cause many complications. We
 # thus remove any part of PATH of that has `ccache' in it before making
 # symbolic links to the programs we are not building ourselves.
+#
+# We'll need the system's PATH for making links to low-level programs we
+# won't be building ourselves.
+syspath := $(PATH)
 makelink = origpath="$$PATH"; \
 	export PATH=$$(echo $(syspath) \
 	                    | tr : '\n' \
@@ -322,7 +166,8 @@ makelink = origpath="$$PATH"; \
 	export PATH="$$origpath"
 
 $(ibdir) $(ildir):; mkdir $@
-$(ibidir)/low-level-links: $(ibidir)/coreutils | $(ibdir) $(ildir)
+$(ibidir)/low-level-links: $(ibidir)/coreutils-$(coreutils-version) \
+                           | $(ibdir) $(ildir)
 
         # Not-installed (but necessary in some cases) compilers.
         #  Clang is necessary for CMake.
@@ -331,6 +176,7 @@ $(ibidir)/low-level-links: $(ibidir)/coreutils | $(ibdir) $(ildir)
 
         # Mac OS specific
 	$(call makelink,mig)
+	$(call makelink,xcrun)
 	$(call makelink,sysctl)
 	$(call makelink,sw_vers)
 	$(call makelink,dsymutil)
@@ -374,17 +220,25 @@ $(ibidir)/low-level-links: $(ibidir)/coreutils | $(ibdir) $(ildir)
 # tarballs of the other compression programs. Once all the compression
 # programs/libraries are complete, we build our own GNU Tar and continue
 # with other software.
-$(ibidir)/gzip: $(tdir)/gzip-$(gzip-version).tar.lz
-	$(call gbuild, gzip-$(gzip-version), static, , V=1) \
-	&& echo "GNU Gzip $(gzip-version)" > $@
+$(lockdir): | $(BDIR); mkdir $@
+$(ibidir)/gzip-$(gzip-version): | $(ibdir) $(ildir) $(lockdir)
+	tarball=gzip-$(gzip-version).tar.lz
+	$(call import-source, $(gzip-url), $(gzip-checksum))
+	$(call gbuild, gzip-$(gzip-version), static, , V=1)
+	echo "GNU Gzip $(gzip-version)" > $@
+
+$(ibidir)/xz-$(xz-version): $(ibidir)/gzip-$(gzip-version)
+	tarball=xz-$(xz-version).tar.gz
+	$(call import-source, $(xz-url), $(xz-checksum))
+	$(call gbuild, xz-$(xz-version), static)
+	echo "XZ Utils $(xz-version)" > $@
 
-$(ibidir)/xz: $(ibidir)/gzip \
-              $(tdir)/xz-$(xz-version).tar.gz
-	$(call gbuild, xz-$(xz-version), static) \
-	&& echo "XZ Utils $(xz-version)" > $@
+$(ibidir)/bzip2-$(bzip2-version): $(ibidir)/gzip-$(gzip-version)
+
+        # Download the tarball.
+	tarball=bzip2-$(bzip2-version).tar.gz
+	$(call import-source, $(bzip2-url), $(bzip2-checksum))
 
-$(ibidir)/bzip2: $(ibidir)/gzip \
-                 $(tdir)/bzip2-$(bzip2-version).tar.gz
         # Bzip2 doesn't have a `./configure' script, and its Makefile
         # doesn't build a shared library. So we can't use the `gbuild'
         # function here and we need to take some extra steps (inspired
@@ -406,71 +260,77 @@ $(ibidir)/bzip2: $(ibidir)/gzip \
 	    makeshared="make -f Makefile-libbz2_so"
 	  fi
 	fi
-	cd $(ddir) && rm -rf $$tdir \
-	&& tar xf $(word 1,$(filter $(tdir)/%,$^)) \
-	&& cd $$tdir \
-	&& sed -e 's@\(ln -s -f \)$$(PREFIX)/bin/@\1@' Makefile \
-	       > Makefile.sed \
-	&& mv Makefile.sed Makefile \
-	&& $$makeshared CC=cc \
-	&& cp -a libbz2* $(ildir)/ \
-	&& make clean \
-	&& $$makecommand CC=cc \
-	&& make install PREFIX=$(idir) \
-	&& cd .. \
-	&& rm -rf $$tdir \
-	&& cd $(ildir) \
-	&& ln -fs libbz2.so.1.0 libbz2.so \
-	&& echo "Bzip2 $(bzip2-version)" > $@
-
-$(ibidir)/unzip: $(ibidir)/gzip \
-                 $(tdir)/unzip-$(unzip-version).tar.gz
+	cd $(ddir)
+	rm -rf $$tdir
+	tar xf $(tdir)/$$tarball
+	cd $$tdir
+	sed -e 's@\(ln -s -f \)$$(PREFIX)/bin/@\1@' Makefile \
+	    > Makefile.sed
+	mv Makefile.sed Makefile
+	$$makeshared CC=cc
+	cp -a libbz2* $(ildir)/
+	make clean
+	$$makecommand CC=cc
+	make install PREFIX=$(idir)
+	cd ..
+	rm -rf $$tdir
+	cd $(ildir)
+	ln -fs libbz2.so.1.0 libbz2.so
+	echo "Bzip2 $(bzip2-version)" > $@
+
+$(ibidir)/unzip-$(unzip-version): $(ibidir)/gzip-$(gzip-version)
+	tarball=unzip-$(unzip-version).tar.gz
 	v=$$(echo $(unzip-version) | sed -e's/\.//')
+	$(call import-source, $(unzip-url), $(unzip-checksum))
 	$(call gbuild, unzip$$v, static,, \
 	               -f unix/Makefile generic \
 	               CFLAGS="-DBIG_MEM -DMMAP",,pwd, \
 	               -f unix/Makefile generic \
-	               BINDIR=$(ibdir) MANDIR=$(idir)/man/man1 ) \
-	&& echo "Unzip $(unzip-version)" > $@
+	               BINDIR=$(ibdir) MANDIR=$(idir)/man/man1 )
+	echo "Unzip $(unzip-version)" > $@
 
-$(ibidir)/zip: $(ibidir)/gzip \
-               $(tdir)/zip-$(zip-version).tar.gz
+$(ibidir)/zip-$(zip-version): $(ibidir)/gzip-$(gzip-version)
+	tarball=zip-$(zip-version).tar.gz
 	v=$$(echo $(zip-version) | sed -e's/\.//')
+	$(call import-source, $(zip-url), $(zip-checksum))
 	$(call gbuild, zip$$v, static,, \
 	               -f unix/Makefile generic \
 	               CFLAGS="-DBIG_MEM -DMMAP",,pwd, \
 	               -f unix/Makefile generic \
-	               BINDIR=$(ibdir) MANDIR=$(idir)/man/man1 ) \
-	&& echo "Zip $(zip-version)" > $@
+	               BINDIR=$(ibdir) MANDIR=$(idir)/man/man1 )
+	echo "Zip $(zip-version)" > $@
 
 # Some programs (like Wget and CMake) that use zlib need it to be dynamic
 # so they use our custom build. So we won't force a static-only build.
 #
 # Note for a static-only build: Zlib's `./configure' doesn't use Autoconf's
 # configure script, it just accepts a direct `--static' option.
-$(ibidir)/zlib: $(ibidir)/gzip \
-                $(tdir)/zlib-$(zlib-version).tar.gz
-	$(call gbuild, zlib-$(zlib-version)) \
-	&& echo "Zlib $(zlib-version)" > $@
+$(ibidir)/zlib-$(zlib-version): $(ibidir)/gzip-$(gzip-version)
+	tarball=zlib-$(zlib-version).tar.gz
+	$(call import-source, $(zlib-url), $(zlib-checksum))
+	$(call gbuild, zlib-$(zlib-version))
+	echo "Zlib $(zlib-version)" > $@
 
 # GNU Tar: When built statically, tar gives a segmentation fault on
 # unpacking Bash. So we'll build it dynamically. Note that technically, zip
 # and unzip aren't dependencies of Tar, but for a clean build, we'll set
 # Tar to be the last compression-related software (the first-set of
 # software to be built).
-$(ibidir)/tar: $(ibidir)/xz \
-               $(ibidir)/zip \
-               $(ibidir)/gzip \
-               $(ibidir)/zlib \
-               $(ibidir)/bzip2 \
-               $(ibidir)/unzip \
-               $(tdir)/tar-$(tar-version).tar.gz
+$(ibidir)/tar-$(tar-version): \
+              $(ibidir)/xz-$(xz-version) \
+              $(ibidir)/zip-$(zip-version) \
+              $(ibidir)/gzip-$(gzip-version) \
+              $(ibidir)/zlib-$(zlib-version) \
+              $(ibidir)/bzip2-$(bzip2-version) \
+              $(ibidir)/unzip-$(unzip-version)
         # Since all later programs depend on Tar, the configuration will be
         # stuck here, only making Tar. So its more efficient to built it on
         # multiple threads (when the user's Make doesn't pass down the
         # number of threads).
-	$(call gbuild, tar-$(tar-version), , , -j$(numthreads) V=1) \
-	&& echo "GNU Tar $(tar-version)" > $@
+	tarball=tar-$(tar-version).tar.gz
+	$(call import-source, $(tar-url), $(tar-checksum))
+	$(call gbuild, tar-$(tar-version), , , -j$(numthreads) V=1)
+	echo "GNU Tar $(tar-version)" > $@
 
 
 
@@ -481,8 +341,34 @@ $(ibidir)/tar: $(ibidir)/xz \
 
 
 
-# Level 2 (SECOND MOST BASIC): Bash and Make
-# ------------------------------------------
+# Level 2 (necessary for linking)
+#
+# Patchelf is necessary for some software on GNU/Linux systems, its job is
+# to manually insert RPATH into the dynamically-linked executable. Since
+# all the other software depend on Pathelf, to avoid manually repeating as
+# a prerequisite (and forgetting in others causing bugs), we'll put it as a
+# dependancy of 'tar'.
+$(ibidir)/patchelf-$(patchelf-version): $(ibidir)/tar-$(tar-version)
+	tarball=patchelf-$(patchelf-version).tar.gz
+	$(call import-source, $(patchelf-url), $(patchelf-checksum))
+	if [ x$(on_mac_os) = xyes ]; then
+	  echo "" > $@
+	else
+	  $(call gbuild, patchelf-$(patchelf-version))
+	  echo "PatchELF $(patchelf-version)" > $@
+	fi
+
+
+
+
+
+
+
+
+
+
+# Level 3 (THIRD MOST BASIC): Bash
+# --------------------------------
 #
 # GNU Make and GNU Bash are the second layer that we'll need to build the
 # basic dependencies.
@@ -492,8 +378,9 @@ $(ibidir)/tar: $(ibidir)/xz \
 # function (for tilde expansion). The first can be disabled with
 # `--disable-load', but unfortunately I don't know any way to fix the
 # second. So, we'll have to build it dynamically for now.
-$(ibidir)/ncurses: $(ibidir)/tar \
-                   $(tdir)/ncurses-$(ncurses-version).tar.gz
+$(ibidir)/ncurses-$(ncurses-version): $(ibidir)/patchelf-$(patchelf-version)
+	tarball=ncurses-$(ncurses-version).tar.gz
+	$(call import-source, $(ncurses-url), $(ncurses-checksum))
 
         # Delete the library that will be installed (so we can make sure
         # the build process completed afterwards and reset the links).
@@ -578,17 +465,14 @@ $(ibidir)/ncurses: $(ibidir)/tar \
 	  exit 1
 	fi
 
-$(ibidir)/readline: $(ibidir)/ncurses \
-                    $(tdir)/readline-$(readline-version).tar.gz
+$(ibidir)/readline-$(readline-version): \
+                   $(ibidir)/ncurses-$(ncurses-version)
+	tarball=readline-$(readline-version).tar.gz
+	$(call import-source, $(readline-url), $(readline-checksum))
 	$(call gbuild, readline-$(readline-version), static, \
 	               --with-curses --disable-install-examples, \
-	               SHLIB_LIBS="-lncursesw" -j$(numthreads)) \
-	&& echo "GNU Readline $(readline-version)" > $@
-
-$(ibidir)/patchelf: $(ibidir)/tar \
-                    $(tdir)/patchelf-$(patchelf-version).tar.gz
-	$(call gbuild, patchelf-$(patchelf-version)) \
-	&& echo "PatchELF $(patchelf-version)" > $@
+	               SHLIB_LIBS="-lncursesw" -j$(numthreads))
+	echo "GNU Readline $(readline-version)" > $@
 
 
 # IMPORTANT: Even though we have enabled `rpath', Bash doesn't write the
@@ -620,16 +504,13 @@ $(ibidir)/patchelf: $(ibidir)/tar \
 #   $ tar cf bash-5.0.$number.tar bash-5.0.$number
 #   $ lzip --best bash-5.0.$number.tar
 #   $ rm -rf bash50-* bash-5.0.$number bash-5.0.tar.gz
+$(ibidir)/bash-$(bash-version): \
+               $(ibidir)/gettext-$(gettext-version) \
+               $(ibidir)/readline-$(readline-version)
 
-ifeq ($(on_mac_os),yes)
-needpatchelf =
-else
-needpatchelf = $(ibidir)/patchelf
-endif
-$(ibidir)/bash: $(needpatchelf) \
-                $(ibidir)/gettext \
-                $(ibidir)/readline \
-                $(tdir)/bash-$(bash-version).tar.lz
+        # Download the tarball.
+	tarball=bash-$(bash-version).tar.lz
+	$(call import-source, $(bash-url), $(bash-checksum))
 
         # Delete the (possibly) existing Bash executable in the project,
         # let it use the default shell of the host.
@@ -655,9 +536,8 @@ $(ibidir)/bash: $(needpatchelf) \
         # default. So, we have to manually include it, currently we are
         # only doing this on GNU/Linux systems (using the `patchelf'
         # program).
-	if [ "x$(needpatchelf)" != x ]; then
-	  if [ -f $(ibdir)/bash ]; then
-	    $(ibdir)/patchelf --set-rpath $(ildir) $(ibdir)/bash; fi
+	if [ -f $(ibdir)/patchelf ]; then
+	  $(ibdir)/patchelf --set-rpath $(ildir) $(ibdir)/bash;
 	fi
 
         # To be generic, some systems use the `sh' command to call the
@@ -668,11 +548,8 @@ $(ibidir)/bash: $(needpatchelf) \
         # Just to be sure that the installation step above went well,
         # before making the link, we'll see if the file actually exists
         # there.
-	if [ -f $(ibdir)/bash ]; then
-	  ln -fs $(ibdir)/bash $(ibdir)/sh
-	  echo "GNU Bash $(bash-version)" > $@
-	else
-	  echo "GNU Bash not built!"; exit 1; fi
+	ln -fs $(ibdir)/bash $(ibdir)/sh
+	echo "GNU Bash $(bash-version)" > $@
 
 
 
@@ -688,46 +565,45 @@ perl-conflddlflags =
 else
 perl-conflddlflags = -Dlddlflags="-shared $$LDFLAGS"
 endif
-$(ibidir)/perl: $(ibidir)/tar \
-                $(tdir)/perl-$(perl-version).tar.gz
+$(ibidir)/perl-$(perl-version): $(ibidir)/patchelf-$(patchelf-version)
+	tarball=perl-$(perl-version).tar.gz
+	$(call import-source, $(perl-url), $(perl-checksum))
 	major_version=$$(echo $(perl-version) \
 	                     | sed -e's/\./ /g' \
 	                     | awk '{printf("%d", $$1)}')
 	base_version=$$(echo $(perl-version) \
 	                     | sed -e's/\./ /g' \
 	                     | awk '{printf("%d.%d", $$1, $$2)}')
-	cd $(ddir) \
-	&& rm -rf perl-$(perl-version) \
-	&& if ! tar xf $(word 1,$(filter $(tdir)/%,$^)); then \
-	      echo; echo "Tar error"; exit 1; \
-	   fi \
-	&& cd perl-$(perl-version) \
-	&& ./Configure -des \
-	               -Dusethreads \
-	               -Duseshrplib \
-	               -Dprefix=$(idir) \
-	               -Dvendorprefix=$(idir) \
-	               -Dprivlib=$(idir)/share/perl$$major_version/core_perl \
-	               -Darchlib=$(idir)/lib/perl$$major_version/$$base_version/core_perl \
-	               -Dsitelib=$(idir)/share/perl$$major_version/site_perl \
-	               -Dsitearch=$(idir)/lib/perl$$major_version/$$basever/site_perl \
-	               -Dvendorlib=$(idir)/share/perl$$major_version/vendor_perl \
-	               -Dvendorarch=$(idir)/lib/perl$$major_version/$$base_version/vendor_perl \
-	               -Dscriptdir=$(idir)/bin/core_perl \
-	               -Dsitescript=$(idir)/bin/site_perl \
-	               -Dvendorscript=$(idir)/bin/vendor_perl \
-	               -Dinc_version_list=none \
-	               -Dman1ext=1perl \
-	               -Dman3ext=3perl \
-	               -Dcccdlflags='-fPIC' \
-	               $(perl-conflddlflags) \
-	               -Dldflags="$$LDFLAGS" \
-	&& make -j$(numthreads) \
-	&& make install \
-	&& cd .. \
-	&& rm -rf perl-$(perl-version) \
-	&& cd $$topdir \
-	&& echo "Perl $(perl-version)" > $@
+	cd $(ddir)
+	rm -rf perl-$(perl-version)
+	tar xf $(tdir)/$$tarball
+	cd perl-$(perl-version)
+	./Configure -des \
+	            -Dusethreads \
+	            -Duseshrplib \
+	            -Dprefix=$(idir) \
+	            -Dvendorprefix=$(idir) \
+	            -Dprivlib=$(idir)/share/perl$$major_version/core_perl \
+	            -Darchlib=$(idir)/lib/perl$$major_version/$$base_version/core_perl \
+	            -Dsitelib=$(idir)/share/perl$$major_version/site_perl \
+	            -Dsitearch=$(idir)/lib/perl$$major_version/$$basever/site_perl \
+	            -Dvendorlib=$(idir)/share/perl$$major_version/vendor_perl \
+	            -Dvendorarch=$(idir)/lib/perl$$major_version/$$base_version/vendor_perl \
+	            -Dscriptdir=$(idir)/bin/core_perl \
+	            -Dsitescript=$(idir)/bin/site_perl \
+	            -Dvendorscript=$(idir)/bin/vendor_perl \
+	            -Dinc_version_list=none \
+	            -Dman1ext=1perl \
+	            -Dman3ext=3perl \
+	            -Dcccdlflags='-fPIC' \
+	            $(perl-conflddlflags) \
+	            -Dldflags="$$LDFLAGS"
+	make -j$(numthreads)
+	make install
+	cd ..
+	rm -rf perl-$(perl-version)
+	cd $$topdir
+	echo "Perl $(perl-version)" > $@
 
 
 
@@ -754,61 +630,70 @@ $(ibidir)/perl: $(ibidir)/tar \
 # an error).
 #
 # Coreutils uses Perl to create man pages!
-$(ibidir)/coreutils: $(ibidir)/bash \
-                     $(ibidir)/perl \
-                     $(ibidir)/openssl \
-                     $(tdir)/coreutils-$(coreutils-version).tar.xz
-	cd $(ddir) \
-	&& rm -rf coreutils-$(coreutils-version) \
-	&& if ! tar xf $(word 1,$(filter $(tdir)/%,$^)); then \
-	      echo; echo "Tar error"; exit 1; \
-	   fi \
-	&& cd coreutils-$(coreutils-version) \
-	&& sed -e's|\#\! /bin/sh|\#\! $(ibdir)/bash|' \
-	       -e's|\#\!/bin/sh|\#\! $(ibdir)/bash|' \
-	       configure > configure-tmp \
-	&& mv configure-tmp configure \
-	&& chmod +x configure \
-	&& ./configure --prefix=$(idir) SHELL=$(ibdir)/bash  \
-	               LDFLAGS="$(LDFLAGS)" CPPFLAGS="$(CPPFLAGS)" \
-	               --disable-silent-rules --with-openssl=yes \
-	&& make SHELL=$(ibdir)/bash -j$(numthreads) \
-	&& make SHELL=$(ibdir)/bash install \
-	&& if [ x$(on_mac_os) != xyes ]; then \
-	     make SHELL=$(ibdir)/bash install DESTDIR=junkinst; \
-	     instprogs=$$(ls junkinst/$(ibdir)); \
-	     for f in $$instprogs; do \
-	       $(ibdir)/patchelf --set-rpath $(ildir) $(ibdir)/$$f; \
-	     done; \
-	     echo "PatchELF applied to all programs."; \
-	   fi \
-	&& cd .. \
-	&& rm -rf coreutils-$(coreutils-version) \
-	&& echo "GNU Coreutils $(coreutils-version)" > $@
+$(ibidir)/coreutils-$(coreutils-version): \
+                    $(ibidir)/bash-$(bash-version) \
+                    $(ibidir)/perl-$(perl-version) \
+                    $(ibidir)/openssl-$(openssl-version)
+
+        # Import, unpack and enter the source directory.
+	tarball=coreutils-$(coreutils-version).tar.xz
+	$(call import-source, $(coreutils-url), $(coreutils-checksum))
+	cd $(ddir)
+	rm -rf coreutils-$(coreutils-version)
+	tar xf $(tdir)/$$tarball
+	cd coreutils-$(coreutils-version)
+
+        # Set the configure script to use our shell, note that we can't
+        # assume GNU SED here yet (it installs after Coreutils).
+	sed -e's|\#\! /bin/sh|\#\! $(ibdir)/bash|' \
+	    -e's|\#\!/bin/sh|\#\! $(ibdir)/bash|' \
+	    configure > configure-tmp
+	mv configure-tmp configure
+	chmod +x configure
+
+        # Configure, build and install Coreutils.
+	./configure --prefix=$(idir) SHELL=$(ibdir)/bash  \
+	            LDFLAGS="$(LDFLAGS)" CPPFLAGS="$(CPPFLAGS)" \
+	            --disable-silent-rules --with-openssl=yes
+	make SHELL=$(ibdir)/bash -j$(numthreads)
+	make SHELL=$(ibdir)/bash install
+
+        # Fix RPATH if necessary.
+	if [ -f $(ibdir)/patchelf ]; then
+	  make SHELL=$(ibdir)/bash install DESTDIR=junkinst
+	  instprogs=$$(ls junkinst/$(ibdir))
+	  for f in $$instprogs; do
+	    $(ibdir)/patchelf --set-rpath $(ildir) $(ibdir)/$$f
+	  done
+	  echo "PatchELF applied to all programs."
+	fi
+
+        # Come back up to the unpacking directory, delete the source
+        # directory and write the final target.
+	cd ..
+	rm -rf coreutils-$(coreutils-version)
+	echo "GNU Coreutils $(coreutils-version)" > $@
 
 # OpenSSL
 #
-# Some programs/libraries later need dynamic linking. So we'll build libssl
-# (and libcrypto) dynamically also.
-#
 # Until we find a nice and generic way to create an updated CA file in the
 # project, the certificates will be available in a file for this project
 # along with the other tarballs.
-#
-# In case you do want a static OpenSSL and libcrypto, then uncomment the
-# following conditional and put $(openssl-static) in the configure options.
-#
-#ifeq ($(static_build),yes)
-#openssl-static = no-dso no-dynamic-engine no-shared
-#endif
 $(idir)/etc:; mkdir $@
-# Note: cert.pm has to be AFTER the tarball, otherwise the build script
-# will try to unpack cert.pm and crash (it unpacks the first dependency
-# under `tdir').
-$(ibidir)/openssl: $(ibidir)/perl \
-                   $(tdir)/openssl-$(openssl-version).tar.gz \
-                   $(tdir)/cert.pem \
-                   | $(idir)/etc
+$(idir)/etc/ssl: | $(idir)/etc; mkdir $@
+$(ibidir)/openssl-$(openssl-version): $(ibidir)/perl-$(perl-version) \
+                  | $(idir)/etc/ssl
+
+        # First download the certificates and copy them into the
+        # installation directory.
+	tarball=cert.pem
+	$(call import-source, $(cert-url), $(cert-checksum))
+	cp $(tdir)/cert.pem $(idir)/etc/ssl/cert.pem
+
+        # Now download the OpenSSL tarball.
+	tarball=openssl-$(openssl-version).tar.gz
+	$(call import-source, $(openssl-url), $(openssl-checksum))
+
         # According to OpenSSL's Wiki (link bellow), it can't automatically
         # detect Mac OS's structure. It will need some help. So we'll use
         # the `on_mac_os' Make variable that we defined in the configure
@@ -816,18 +701,10 @@ $(ibidir)/openssl: $(ibidir)/perl \
         # environment variable.
         #
         # https://wiki.openssl.org/index.php/Compilation_and_Installation
-        #
-        # Bug 58263 (https://savannah.nongnu.org/bugs/?58263): In OpenSSL
-        # Version 1.1.1a (also checked in 1.1.1g), `openssl/ec.h' fails to
-        # include `openssl/openconf.h' on some OSs. The SED hack below
-        # inserts a hardwired element of `openssl/openconf.h' that is
-        # needed to include sections of code `f` that are deprecated in
-        # 1.2.0, but not yet in 1.1.1. This problem may be solved in
-        # version 1.2.x, so please check again in that bug.
-	if [ x$(on_mac_os) = xyes ]; then \
-	  export KERNEL_BITS=64; \
-	  copt="shared no-ssl2 no-ssl3 enable-ec_nistp_64_gcc_128";  \
-	fi; \
+	if [ x$(on_mac_os) = xyes ]; then
+	  export KERNEL_BITS=64
+	  copt="shared no-ssl2 no-ssl3 enable-ec_nistp_64_gcc_128"
+	fi
 	$(call gbuild, openssl-$(openssl-version), , \
 	               zlib \
 	               $$copt \
@@ -835,19 +712,26 @@ $(ibidir)/openssl: $(ibidir)/perl \
 	               --openssldir=$(idir)/etc/ssl \
 	               --with-zlib-lib=$(ildir) \
 	               --with-zlib-include=$(idir)/include, \
-	               -j$(numthreads), , ./config ) \
-	&& mv -v $(idir)/include/openssl/ec.h $(idir)/include/openssl/ec.h.orig \
-	&& sed -e 's,\(# include .openssl/opensslconf\.h.\),\1\n#ifndef DEPRECATEDIN_1_2_0\n#define DEPRECATEDIN_1_2_0(f)   f;\n#endif\n,' \
-	   $(idir)/include/openssl/ec.h.orig > $(idir)/include/openssl/ec.h \
-	&& cp $(tdir)/cert.pem $(idir)/etc/ssl/cert.pem \
-	&& if [ $$? = 0 ]; then \
-	     if [ x$(on_mac_os) = xyes ]; then \
-	       echo "No need to fix rpath in libssl"; \
-	     else \
-	       patchelf --set-rpath $(ildir) $(ildir)/libssl.so; \
-	     fi; \
-	     echo "OpenSSL $(openssl-version)" > $@; \
-	   fi
+	               -j$(numthreads), , ./config )
+
+        # Manually insert RPATH inside the OpenSSL library.
+	if [ -f $(ibdir)/patchelf ]; then
+	   patchelf --set-rpath $(ildir) $(ildir)/libssl.so; \
+	fi
+
+        # Bug 58263 (https://savannah.nongnu.org/bugs/?58263): In OpenSSL
+        # Version 1.1.1a (also checked in 1.1.1g), `openssl/ec.h' fails to
+        # include `openssl/openconf.h' on some OSs. The SED hack below
+        # inserts a hardwired element of `openssl/openconf.h' that is
+        # needed to include sections of code `f` that are deprecated in
+        # 1.2.0, but not yet in 1.1.1. This problem may be solved in
+        # version 1.2.x, so please check again in that bug.
+	mv -v $(idir)/include/openssl/ec.h $(idir)/include/openssl/ec.h.orig
+	sed -e 's,\(# include .openssl/opensslconf\.h.\),\1\n#ifndef DEPRECATEDIN_1_2_0\n#define DEPRECATEDIN_1_2_0(f)   f;\n#endif\n,' \
+	   $(idir)/include/openssl/ec.h.orig > $(idir)/include/openssl/ec.h
+
+        # Build the final target.
+	echo "OpenSSL $(openssl-version)" > $@
 
 
 
@@ -864,8 +748,11 @@ $(ibidir)/openssl: $(ibidir)/perl \
 # them. Note that if it does link with them, the configuration will crash
 # when the library is updated/changed by the host, and the whole purpose of
 # this project is avoid dependency on the host as much as possible.
-$(ibidir)/curl: $(ibidir)/coreutils \
-                $(tdir)/curl-$(curl-version).tar.gz
+$(ibidir)/curl-$(curl-version): $(ibidir)/coreutils-$(coreutils-version)
+
+	tarball=curl-$(curl-version).tar.gz
+	$(call import-source, $(curl-url), $(curl-checksum))
+
 	$(call gbuild, curl-$(curl-version), , \
 	               LIBS="-pthread" \
 	               --with-zlib=$(ildir) \
@@ -882,11 +769,12 @@ $(ibidir)/curl: $(ibidir)/coreutils \
 	               --without-axtls \
 	               --disable-ldaps \
 	               --disable-ldap \
-	               --without-nss, V=1) \
-	&& if [ "x$(needpatchelf)" != x ]; then \
-	     $(ibdir)/patchelf --set-rpath $(ildir) $(ildir)/libcurl.so; \
-	   fi \
-	&& echo "cURL $(curl-version)" > $@
+	               --without-nss, V=1)
+
+	if [ -f $(ibdir)/patchelf ]; then
+	   $(ibdir)/patchelf --set-rpath $(ildir) $(ildir)/libcurl.so
+	fi
+	echo "cURL $(curl-version)" > $@
 
 
 # GNU Wget
@@ -902,13 +790,18 @@ $(ibidir)/curl: $(ibidir)/coreutils \
 # building as part of this project. So to avoid too much dependency on the
 # host system (especially a crash when these libraries are updated on the
 # host), they are disabled here.
-$(ibidir)/wget: $(ibidir)/libiconv \
-                $(ibidir)/coreutils \
-                $(tdir)/wget-$(wget-version).tar.lz
+$(ibidir)/wget-$(wget-version): \
+               $(ibidir)/libiconv-$(libiconv-version) \
+               $(ibidir)/coreutils-$(coreutils-version)
+
+        # Download the tarball.
+	tarball=wget-$(wget-version).tar.lz
+	$(call import-source, $(wget-url), $(wget-checksum))
+
         # We need to explicitly disable `libiconv', because of the
         # `pkg-config' and `libiconv' problem.
-	libs="-pthread"; \
-	if [ x$(needs_ldl) = xyes ]; then libs="$$libs -ldl"; fi; \
+	libs="-pthread"
+	if [ x$(needs_ldl) = xyes ]; then libs="$$libs -ldl"; fi
 	$(call gbuild, wget-$(wget-version), , \
 	               LIBS="$$LIBS $$libs" \
 	               --with-libssl-prefix=$(idir) \
@@ -921,8 +814,8 @@ $(ibidir)/wget: $(ibidir)/libiconv \
 	               --without-libidn \
 	               --disable-pcre2 \
 	               --disable-pcre \
-	               --disable-iri, V=1) \
-	&& echo "GNU Wget $(wget-version)" > $@
+	               --disable-iri, V=1 -j$(numthreads))
+	echo "GNU Wget $(wget-version)" > $@
 
 
 
@@ -937,138 +830,172 @@ $(ibidir)/wget: $(ibidir)/libiconv \
 # process of the higher-level programs and libraries. Note that during the
 # building of those higher-level programs (after this Makefile finishes),
 # there is no access to the system's PATH.
-$(ibidir)/diffutils: $(ibidir)/coreutils \
-                     $(tdir)/diffutils-$(diffutils-version).tar.xz
-	$(call gbuild, diffutils-$(diffutils-version), static,,V=1) \
-	&& echo "GNU Diffutils $(diffutils-version)" > $@
-
-$(ibidir)/file: $(ibidir)/coreutils \
-                $(tdir)/file-$(file-version).tar.gz
-	$(call gbuild, file-$(file-version), static,,V=1) \
-	&& echo "File $(file-version)" > $@
-
-$(ibidir)/findutils: $(ibidir)/coreutils \
-                     $(tdir)/findutils-$(findutils-version).tar.xz
-	$(call gbuild, findutils-$(findutils-version), static,,V=1) \
-	&& echo "GNU Findutils $(findutils-version)" > $@
-
-$(ibidir)/gawk: $(ibidir)/gmp \
-                $(ibidir)/mpfr \
-                $(ibidir)/coreutils \
-                $(tdir)/gawk-$(gawk-version).tar.lz
+$(ibidir)/diffutils-$(diffutils-version): \
+                    $(ibidir)/coreutils-$(coreutils-version)
+	tarball=diffutils-$(diffutils-version).tar.xz
+	$(call import-source, $(diffutils-url), $(diffutils-checksum))
+	$(call gbuild, diffutils-$(diffutils-version), static,,V=1)
+	echo "GNU Diffutils $(diffutils-version)" > $@
+
+$(ibidir)/file-$(file-version): $(ibidir)/coreutils-$(coreutils-version)
+	tarball=file-$(file-version).tar.gz
+	$(call import-source, $(file-url), $(file-checksum))
+	$(call gbuild, file-$(file-version), static,,V=1)
+	echo "File $(file-version)" > $@
+
+$(ibidir)/findutils-$(findutils-version): \
+                    $(ibidir)/coreutils-$(coreutils-version)
+	tarball=findutils-$(findutils-version).tar.xz
+	$(call import-source, $(findutils-url), $(findutils-checksum))
+	$(call gbuild, findutils-$(findutils-version), static,,V=1)
+	echo "GNU Findutils $(findutils-version)" > $@
+
+$(ibidir)/gawk-$(gawk-version): \
+               $(ibidir)/gmp-$(gmp-version) \
+               $(ibidir)/mpfr-$(mpfr-version) \
+               $(ibidir)/coreutils-$(coreutils-version)
+
+        # Download the tarball.
+	tarball=gawk-$(gawk-version).tar.lz
+	$(call import-source, $(gawk-url), $(gawk-checksum))
+
         # AWK doesn't include RPATH by default, so we'll have to manually
         # include it using the `patchelf' program (which was a dependency
         # of Bash). Just note that AWK produces two executables (for
         # example `gawk-4.2.1' and `gawk') and a symbolic link `awk' to one
         # of those executables.
 	$(call gbuild, gawk-$(gawk-version), static, \
-	               --with-readline=$(idir)) \
-	&& if [ "x$(needpatchelf)" != x ]; then \
-	     if [ -f $(ibdir)/gawk ]; then \
-	       $(ibdir)/patchelf --set-rpath $(ildir) $(ibdir)/gawk; \
-	     fi; \
-	     if [ -f $(ibdir)/gawk-$(gawk-version) ]; then \
-	       $(ibdir)/patchelf --set-rpath $(ildir) \
-	                         $(ibdir)/gawk-$(gawk-version); \
-	    fi; \
-	   fi \
-	&& echo "GNU AWK $(gawk-version)" > $@
-
-$(ibidir)/libiconv: $(ibidir)/pkg-config \
-                    $(tdir)/libiconv-$(libiconv-version).tar.gz
-	$(call gbuild, libiconv-$(libiconv-version), static) \
-	&& echo "GNU libiconv $(libiconv-version)" > $@
-
-$(ibidir)/libunistring: $(ibidir)/libiconv \
-                        $(tdir)/libunistring-$(libunistring-version).tar.xz
+	               --with-readline=$(idir))
+
+        # Correct the RPATH on systems that have installed patchelf.
+	if [ -f $(ibdir)/patchelf ]; then
+	  if [ -f $(ibdir)/gawk ]; then
+	    $(ibdir)/patchelf --set-rpath $(ildir) $(ibdir)/gawk
+	  fi
+	  if [ -f $(ibdir)/gawk-$(gawk-version) ]; then
+	    $(ibdir)/patchelf --set-rpath $(ildir) \
+	                      $(ibdir)/gawk-$(gawk-version);
+	  fi
+	fi
+
+        # Build final target.
+	echo "GNU AWK $(gawk-version)" > $@
+
+$(ibidir)/libiconv-$(libiconv-version): \
+                   $(ibidir)/pkg-config-$(pkgconfig-version)
+	tarball=libiconv-$(libiconv-version).tar.gz
+	$(call import-source, $(libiconv-url), $(libiconv-checksum))
+	$(call gbuild, libiconv-$(libiconv-version), static)
+	echo "GNU libiconv $(libiconv-version)" > $@
+
+$(ibidir)/libunistring-$(libunistring-version): \
+                       $(ibidir)/libiconv-$(libiconv-version)
+	tarball=libunistring-$(libunistring-version).tar.xz
+	$(call import-source, $(libunistring-url), $(libunistring-checksum))
 	$(call gbuild, libunistring-$(libunistring-version), static,, \
-	               -j$(numthreads)) \
-	&& echo "GNU libunistring $(libunistring-version)" > $@
+	               -j$(numthreads))
+	echo "GNU libunistring $(libunistring-version)" > $@
 
-$(ibidir)/libxml2: $(ibidir)/tar \
-                   $(tdir)/libxml2-$(libxml2-version).tar.gz
+$(ibidir)/libxml2-$(libxml2-version): $(ibidir)/patchelf-$(patchelf-version)
         # The libxml2 tarball also contains Python bindings which are built
         # and installed to a system directory by default. If you don't need
         # the Python bindings, the easiest solution is to compile without
         # Python support: `./configure --without-python'. If you really need
         # the Python bindings, use `--with-python-install-dir=DIR' instead.
+	tarball=libxml2-$(libxml2-version).tar.gz
+	$(call import-source, $(libxml2-url), $(libxml2-checksum))
 	$(call gbuild, libxml2-$(libxml2-version), static, \
-	               --without-python) \
-	&& echo "Libxml2 $(libxml2-version)" > $@
-
-$(ibidir)/gettext: $(ibidir)/m4 \
-                   $(ibidir)/libxml2 \
-                   $(ibidir)/ncurses \
-                   $(ibidir)/libiconv \
-                   $(ibidir)/libunistring \
-                   $(tdir)/gettext-$(gettext-version).tar.xz
-	$(call gbuild, gettext-$(gettext-version), static, V=1) \
-	&& echo "GNU gettext $(gettext-version)" > $@
-
-$(ibidir)/git: $(ibidir)/curl \
-               $(ibidir)/gettext \
-               $(ibidir)/libiconv \
-               $(tdir)/git-$(git-version).tar.xz
-	if [ x$(on_mac_os) = xyes ]; then \
-	  export LDFLAGS="$$LDFLAGS -lcharset"; \
-	fi; \
+	               --without-python, V=1)
+	echo "Libxml2 $(libxml2-version)" > $@
+
+$(ibidir)/gettext-$(gettext-version): \
+                  $(ibidir)/m4-$(m4-version) \
+                  $(ibidir)/libxml2-$(libxml2-version) \
+                  $(ibidir)/ncurses-$(ncurses-version) \
+                  $(ibidir)/libiconv-$(libiconv-version) \
+                  $(ibidir)/libunistring-$(libunistring-version)
+	tarball=gettext-$(gettext-version).tar.xz
+	$(call import-source, $(gettext-url), $(gettext-checksum))
+	$(call gbuild, gettext-$(gettext-version), static,, \
+	               V=1 -j$(numthreads))
+	echo "GNU gettext $(gettext-version)" > $@
+
+$(ibidir)/git-$(git-version): \
+              $(ibidir)/curl-$(curl-version) \
+              $(ibidir)/gettext-$(gettext-version) \
+              $(ibidir)/libiconv-$(libiconv-version)
+	tarball=git-$(git-version).tar.xz
+	if [ x$(on_mac_os) = xyes ]; then
+	  export LDFLAGS="$$LDFLAGS -lcharset"
+	fi
+	$(call import-source, $(git-url), $(git-checksum))
 	$(call gbuild, git-$(git-version), static, \
 	               --without-tcltk --with-shell=$(ibdir)/bash \
-	               --with-iconv=$(idir), V=1) \
-	&& echo "Git $(git-version)" > $@
-
-$(ibidir)/gmp: $(ibidir)/m4 \
-               $(ibidir)/coreutils \
-               $(tdir)/gmp-$(gmp-version).tar.lz
+	               --with-iconv=$(idir), V=1 -j$(numthreads))
+	echo "Git $(git-version)" > $@
+
+$(ibidir)/gmp-$(gmp-version): \
+              $(ibidir)/m4-$(m4-version) \
+              $(ibidir)/coreutils-$(coreutils-version)
+	tarball=gmp-$(gmp-version).tar.lz
+	$(call import-source, $(gmp-url), $(gmp-checksum))
 	$(call gbuild, gmp-$(gmp-version), static, \
-	               --enable-cxx --enable-fat, ,make check)  \
-	&& echo "GNU Multiple Precision Arithmetic Library $(gmp-version)" > $@
+	               --enable-cxx --enable-fat, \
+	               -j$(numthreads) ,make check)
+	echo "GNU Multiple Precision Arithmetic Library $(gmp-version)" > $@
 
 # On Mac OS, libtool does different things, so to avoid confusion, we'll
 # prefix GNU's libtool executables with `glibtool'.
-$(ibidir)/glibtool: $(ibidir)/m4 \
-                    $(tdir)/libtool-$(libtool-version).tar.xz
+$(ibidir)/libtool-$(libtool-version): $(ibidir)/m4-$(m4-version)
+	tarball=libtool-$(libtool-version).tar.xz
+	$(call import-source, $(libtool-url), $(libtool-checksum))
 	$(call gbuild, libtool-$(libtool-version), static, \
-                       --program-prefix=g, V=1) \
-	&& ln -s $(ibdir)/glibtoolize $(ibdir)/libtoolize \
-	&& echo "GNU Libtool $(libtool-version)" > $@
-
-$(ibidir)/grep: $(ibidir)/coreutils \
-                $(tdir)/grep-$(grep-version).tar.xz
-	$(call gbuild, grep-$(grep-version), static,,V=1) \
-	&& echo "GNU Grep $(grep-version)" > $@
-
-$(ibidir)/libbsd: $(ibidir)/coreutils \
-                  $(tdir)/libbsd-$(libbsd-version).tar.xz
-	$(call gbuild, libbsd-$(libbsd-version), static,,V=1) \
-	&& echo "Libbsd $(libbsd-version)" > $@
+                       --program-prefix=g, V=1 -j$(numthreads))
+	ln -s $(ibdir)/glibtoolize $(ibdir)/libtoolize
+	echo "GNU Libtool $(libtool-version)" > $@
+
+$(ibidir)/grep-$(grep-version): $(ibidir)/coreutils-$(coreutils-version)
+	tarball=grep-$(grep-version).tar.xz
+	$(call import-source, $(grep-url), $(grep-checksum))
+	$(call gbuild, grep-$(grep-version), static,,V=1)
+	echo "GNU Grep $(grep-version)" > $@
+
+$(ibidir)/libbsd-$(libbsd-version): $(ibidir)/coreutils-$(coreutils-version)
+	tarball=libbsd-$(libbsd-version).tar.xz
+	$(call import-source, $(libbsd-url), $(libbsd-checksum))
+	if [ x$(on_mac_os) = xyes ]; then
+	  echo "" > $@
+	else
+	  $(call gbuild, libbsd-$(libbsd-version), static,,V=1)
+	  echo "Libbsd $(libbsd-version)" > $@
+	fi
 
 # We need to apply a patch to the M4 source to be used properly on macOS.
 # The patch [1] was inspired by Homebrew's build instructions [1].
 #
 # [1] https://raw.githubusercontent.com/macports/macports-ports/edf0ee1e2cf/devel/m4/files/secure_snprintf.patch
 # [2] https://github.com/Homebrew/homebrew-core/blob/master/Formula/m4.rb
-$(ibidir)/m4: $(ibidir)/texinfo \
-              $(tdir)/m4-$(m4-version).tar.gz
-	cd $(ddir); \
-	unpackdir=m4-$(m4-version); \
-	rm -rf $$unpackdir \
-	&& if ! tar xf $(word 1,$(filter $(tdir)/%,$^)); then \
-	      echo; echo "Tar error"; exit 1; \
-	   fi \
-	&& cd $$unpackdir \
-	&& if [ x$(on_mac_os) = xyes ]; then \
-	     sed 's|if !(((__GLIBC__ > 2|if !defined(__APPLE__) \&\& !(((__GLIBC__ > 2|' \
-	         lib/vasnprintf.c > lib/vasnprintf_edited.c;  \
-	     mv lib/vasnprintf_edited.c lib/vasnprintf.c; \
-	   fi \
-	&& ./configure --prefix=$(idir) LDFLAGS="$(LDFLAGS)" \
-	               CPPFLAGS="$(CPPFLAGS)" \
-	&& make V=1 -j$(numthreads) \
-	&& make V=1 install \
-	&& cd .. \
-	&& rm -rf $$unpackdir \
-	&& echo "GNU M4 $(m4-version)" > $@
+$(ibidir)/m4-$(m4-version): $(ibidir)/texinfo-$(texinfo-version)
+	tarball=m4-$(m4-version).tar.gz
+	$(call import-source, $(m4-url), $(m4-checksum))
+	cd $(ddir)
+	unpackdir=m4-$(m4-version)
+	rm -rf $$unpackdir
+	tar xf $(tdir)/$$tarball
+	mv m4-* $$unpackdir
+	cd $$unpackdir
+	if [ x$(on_mac_os) = xyes ]; then
+	   sed 's|if !(((__GLIBC__ > 2|if !defined(__APPLE__) \&\& !(((__GLIBC__ > 2|' \
+	       lib/vasnprintf.c > lib/vasnprintf_edited.c
+	   mv lib/vasnprintf_edited.c lib/vasnprintf.c
+	fi
+	./configure --prefix=$(idir) LDFLAGS="$(LDFLAGS)" \
+	            CPPFLAGS="$(CPPFLAGS)"
+	make V=1 -j$(numthreads)
+	make V=1 install
+	cd ..
+	rm -rf $$unpackdir
+	echo "GNU M4 $(m4-version)" > $@
 
 # Metastore is used (through a Git hook) to restore the source modification
 # dates of files after a Git checkout. Another Git hook saves all file
@@ -1087,17 +1014,16 @@ $(ibidir)/m4: $(ibidir)/texinfo \
 #
 # Libbsd is not necessary on macOS systems, because macOS is already a
 # BSD-based distribution. But on GNU/Linux systems, it is necessary.
-ifeq ($(on_mac_os),yes)
-needlibbsd =
-else
-needlibbsd = $(ibidir)/libbsd
-endif
-$(ibidir)/metastore: $(needlibbsd) \
-                     $(ibidir)/sed \
-                     $(ibidir)/git \
-                     $(ibidir)/gawk \
-                     $(ibidir)/coreutils \
-                     $(tdir)/metastore-$(metastore-version).tar.gz
+$(ibidir)/metastore-$(metastore-version): \
+                    $(ibidir)/sed-$(sed-version) \
+                    $(ibidir)/git-$(git-version) \
+                    $(ibidir)/gawk-$(gawk-version) \
+                    $(ibidir)/libbsd-$(libbsd-version) \
+                    $(ibidir)/coreutils-$(coreutils-version)
+
+        # Download the tarball.
+	tarball=metastore-$(metastore-version).tar.gz
+	$(call import-source, $(metastore-url), $(metastore-checksum))
 
         # Metastore doesn't have any `./configure' script. So we'll just
         # call `pwd' as a place-holder for the `./configure' command.
@@ -1114,54 +1040,61 @@ $(ibidir)/metastore: $(needlibbsd) \
         # are currently only available in a fork of `metastore' hosted at:
         # https://github.com/mohammad-akhlaghi/metastore
         #
-        # We want to inform the user if Metastore isn't built, so we don't
-        # continue the call to `gbuild' with an `&&'.
-        #
         # Checking for presence of `.git'. When the project source is
         # downloaded from a non-Git source (for example from arXiv), there
         # is no `.git' directory to work with. So until we find a better
         # solution, avoid the step to to add the Git hooks.
 	current_dir=$$(pwd); \
 	$(call gbuild, metastore-$(metastore-version), static,, \
-	               NO_XATTR=1 V=1,,pwd,PREFIX=$(idir)); \
-	if [ -f $(ibdir)/metastore ]; then \
-	  if [ "x$(needpatchelf)" != x ]; then \
-	    $(ibdir)/patchelf --set-rpath $(ildir) $(ibdir)/metastore; \
-	  fi; \
-	  if [ -d .git ]; then \
-	    user=$$(whoami); \
-	    group=$$(groups | awk '{print $$1}'); \
-	    cd $$current_dir; \
-	    for f in pre-commit post-checkout; do \
+	               NO_XATTR=1 V=1,,pwd,PREFIX=$(idir))
+
+        # Correct RPATH when necessary.
+	if [ -f $(ibdir)/patchelf ]; then
+	  $(ibdir)/patchelf --set-rpath $(ildir) $(ibdir)/metastore
+	fi
+
+        # If this project is being built in a directory version controlled
+        # by Git, copy the hooks into the Git configuation.
+	if [ -f $(ibdir)/metastore ]; then
+	  if [ -d .git ]; then
+	    user=$$(whoami)
+	    group=$$(groups | awk '{print $$1}')
+	    cd $$current_dir
+	    for f in pre-commit post-checkout; do
 	       sed -e's|@USER[@]|'$$user'|g' \
 	           -e's|@GROUP[@]|'$$group'|g' \
 	           -e's|@BINDIR[@]|$(ibdir)|g' \
 	           -e's|@TOP_PROJECT_DIR[@]|'$$current_dir'|g' \
-	           reproduce/software/shell/git-$$f > .git/hooks/$$f \
-	       && chmod +x .git/hooks/$$f; \
-	    done; \
-	  fi \
-	  && echo "Metastore (forked) $(metastore-version)" > $@; \
-	else \
-	  echo; echo; echo; \
-	  echo "*****************"; \
-	  echo "metastore couldn't be installed!"; \
-	  echo; \
-	  echo "Its used for preserving timestamps on Git commits."; \
-	  echo "Its useful for development, not simple running of "; \
-	  echo "the project. So we won't stop the configuration "; \
-	  echo "because it wasn't built."; \
-	  echo "*****************"; \
+	           reproduce/software/shell/git-$$f > .git/hooks/$$f
+	       chmod +x .git/hooks/$$f
+	    done
+	  fi
+	  echo "Metastore (forked) $(metastore-version)" > $@
+	else
+	  echo; echo; echo
+	  echo "*****************"
+	  echo "metastore couldn't be installed!"
+	  echo
+	  echo "Its used for preserving timestamps on Git commits."
+	  echo "Its useful for development, not simple running of "
+	  echo "the project. So we won't stop the configuration "
+	  echo "because it wasn't built."
+	  echo "*****************"
+	  echo "" > $@
 	fi
 
+$(ibidir)/mpfr-$(mpfr-version): $(ibidir)/gmp-$(gmp-version)
+	tarball=mpfr-$(mpfr-version).tar.xz
+	$(call import-source, $(mpfr-url), $(mpfr-checksum))
+	$(call gbuild, mpfr-$(mpfr-version), static, , , make check)
+	echo "GNU Multiple Precision Floating-Point Reliably $(mpfr-version)" > $@
 
-$(ibidir)/mpfr: $(ibidir)/gmp \
-                $(tdir)/mpfr-$(mpfr-version).tar.xz
-	$(call gbuild, mpfr-$(mpfr-version), static, , , make check)  \
-	&& echo "GNU Multiple Precision Floating-Point Reliably $(mpfr-version)" > $@
+$(ibidir)/pkg-config-$(pkgconfig-version): $(ibidir)/patchelf-$(patchelf-version)
+
+        # Download the tarball.
+	tarball=pkg-config-$(pkgconfig-version).tar.gz
+	$(call import-source, $(pkgconfig-url), $(pkgconfig-checksum))
 
-$(ibidir)/pkg-config: $(ibidir)/tar \
-                      $(tdir)/pkg-config-$(pkgconfig-version).tar.gz
         # An existing `libiconv' can cause a conflict with `pkg-config',
         # this is why `libiconv' depends on `pkg-config'. On a clean build,
         # `pkg-config' is built first. But when we don't have a clean build
@@ -1174,32 +1107,36 @@ $(ibidir)/pkg-config: $(ibidir)/tar \
         # (GCC) installed that doesn't support some necessary features of
         # building Glib (as part of pkg-config). So to be safe, for Mac
         # systems, we'll make sure it will use LLVM's Clang.
-	if [ x$(on_mac_os) = xyes ]; then export compiler="CC=clang"; \
-	else                              export compiler=""; \
-	fi; \
+	if [ x$(on_mac_os) = xyes ]; then export compiler="CC=clang"
+	else                              export compiler=""
+	fi
 	$(call gbuild, pkg-config-$(pkgconfig-version), static, \
 	               $$compiler --with-internal-glib \
-	               --with-pc-path=$(ildir)/pkgconfig, V=1) \
-	&& echo "pkg-config $(pkgconfig-version)" > $@
-
-$(ibidir)/sed: $(ibidir)/coreutils \
-               $(tdir)/sed-$(sed-version).tar.xz
-	$(call gbuild, sed-$(sed-version), static,,V=1) \
-	&& echo "GNU Sed $(sed-version)" > $@
-
-$(ibidir)/texinfo: $(ibidir)/perl \
-                   $(tdir)/texinfo-$(texinfo-version).tar.xz
-	$(call gbuild, texinfo-$(texinfo-version), static) \
-	&& if [ "x$(needpatchelf)" != x ]; then \
-	     $(ibdir)/patchelf --set-rpath $(ildir) $(ibdir)/info; \
-	     $(ibdir)/patchelf --set-rpath $(ildir) $(ibdir)/install-info; \
-	   fi \
-	&& echo "GNU Texinfo $(texinfo-version)" > $@
+	               --with-pc-path=$(ildir)/pkgconfig, V=1)
+	echo "pkg-config $(pkgconfig-version)" > $@
+
+$(ibidir)/sed-$(sed-version): $(ibidir)/coreutils-$(coreutils-version)
+	tarball=sed-$(sed-version).tar.xz
+	$(call import-source, $(sed-url), $(sed-checksum))
+	$(call gbuild, sed-$(sed-version), static,,V=1)
+	echo "GNU Sed $(sed-version)" > $@
+
+$(ibidir)/texinfo-$(texinfo-version): \
+                  $(ibidir)/perl-$(perl-version)
+	tarball=texinfo-$(texinfo-version).tar.xz
+	$(call import-source, $(texinfo-url), $(texinfo-checksum))
+	$(call gbuild, texinfo-$(texinfo-version), static)
+	if [ -f $(ibdir)/patchelf ]; then
+	  $(ibdir)/patchelf --set-rpath $(ildir) $(ibdir)/info
+	  $(ibdir)/patchelf --set-rpath $(ildir) $(ibdir)/install-info
+	fi
+	echo "GNU Texinfo $(texinfo-version)" > $@
 
-$(ibidir)/which: $(ibidir)/coreutils \
-                 $(tdir)/which-$(which-version).tar.gz
-	$(call gbuild, which-$(which-version), static) \
-	&& echo "GNU Which $(which-version)" > $@
+$(ibidir)/which-$(which-version): $(ibidir)/coreutils-$(coreutils-version)
+	tarball=/which-$(which-version).tar.gz
+	$(call import-source, $(which-url), $(which-checksum))
+	$(call gbuild, which-$(which-version), static)
+	echo "GNU Which $(which-version)" > $@
 
 
 
@@ -1212,80 +1149,86 @@ $(ibidir)/which: $(ibidir)/coreutils \
 
 # GCC and its prerequisites
 # -------------------------
+$(ibidir)/isl-$(isl-version): $(ibidir)/gmp-$(gmp-version)
+	tarball=isl-$(isl-version).tar.bz2
+	$(call import-source, $(isl-url), $(isl-checksum))
+	if [ $(host_cc) = 1 ]; then
+	  echo "" > $@
+	else
+	  $(call gbuild, isl-$(isl-version), static, , \
+	                 V=1 -j$(numthreads))
+	  echo "GNU Integer Set Library $(isl-version)" > $@
+	fi
 
-$(ibidir)/isl: $(ibidir)/gmp \
-               $(tdir)/isl-$(isl-version).tar.bz2
-	$(call gbuild, isl-$(isl-version), static, , V=1)  \
-	&& echo "GNU Integer Set Library $(isl-version)" > $@
-
-$(ibidir)/mpc: $(ibidir)/mpfr \
-               $(tdir)/mpc-$(mpc-version).tar.gz
-	$(call gbuild, mpc-$(mpc-version), static, , , make check)  \
-	&& echo "GNU Multiple Precision Complex library" > $@
-
-# Binutils' assembler (`as') and linker (`ld') will conflict with other
-# compilers. So until then, on Mac systems we'll use the host opertating
-# system's Binutils equivalents by just making links.
-
-ifeq ($(host_cc),1)
-gcc-prerequisites =
-else
-gcc-prerequisites = $(ibidir)/isl \
-                    $(ibidir)/mpc
-endif
-
-ifeq ($(on_mac_os),yes)
-binutils-tarball =
-else
-binutils-tarball = $(tdir)/binutils-$(binutils-version).tar.lz
-endif
+$(ibidir)/mpc-$(mpc-version): $(ibidir)/mpfr-$(mpfr-version)
+	tarball=mpc-$(mpc-version).tar.gz
+	$(call import-source, $(mpc-url), $(mpc-checksum))
+	if [ $(host_cc) = 1 ]; then
+	  echo "" > $@
+	else
+	  $(call gbuild, mpc-$(mpc-version), static, , \
+	                 -j$(numthreads), make check)
+	  echo "GNU Multiple Precision Complex library" > $@
+	fi
 
 # The installation of Binutils can cause problems during the build of other
 # programs (http://savannah.nongnu.org/bugs/?56294). Therefore, we'll set
 # all other basic programs as Binutils prerequisite and GCC (the final
 # basic target) ultimately just depends on Binutils.
-#
-# The `ld' linker of Binutils needs several `*crt*.o' file to run. On some
-# systems these object files aren't installed in standard places. We
-# defined `LIBRARY_PATH' and that fixed the problem for many
-# systems. However, some software (for example ImageMagick) over-write
-# `LIBRARY_PATH', therefore there is no other way than to put a link to
-# these necessary files in our local build directory. IMPORTANT NOTE:
-# later, when we build the GNU C Library in the project, we should remove
-# this step.
-$(ibidir)/binutils: $(ibidir)/sed \
-                    $(ibidir)/wget \
-                    $(ibidir)/grep \
-                    $(ibidir)/file \
-                    $(ibidir)/gawk \
-                    $(ibidir)/which \
-                    $(ibidir)/glibtool \
-                    $(binutils-tarball) \
-                    $(ibidir)/metastore \
-                    $(ibidir)/findutils \
-                    $(ibidir)/diffutils \
-                    $(ibidir)/coreutils \
-                    $(gcc-prerequisites)
-
-	if [ x$(on_mac_os) = xyes ]; then \
-	  $(call makelink,as); \
-	  $(call makelink,ar); \
-	  $(call makelink,ld); \
-	  $(call makelink,nm); \
-	  $(call makelink,ps); \
-	  $(call makelink,ranlib); \
-	  echo "" > $@; \
-	else \
+$(ibidir)/binutils-$(binutils-version): \
+                   $(ibidir)/sed-$(sed-version) \
+                   $(ibidir)/isl-$(isl-version) \
+                   $(ibidir)/mpc-$(mpc-version) \
+                   $(ibidir)/wget-$(wget-version) \
+                   $(ibidir)/grep-$(grep-version) \
+                   $(ibidir)/file-$(file-version) \
+                   $(ibidir)/gawk-$(gawk-version) \
+                   $(ibidir)/which-$(which-version) \
+                   $(ibidir)/libtool-$(libtool-version) \
+                   $(ibidir)/metastore-$(metastore-version) \
+                   $(ibidir)/findutils-$(findutils-version) \
+                   $(ibidir)/diffutils-$(diffutils-version) \
+                   $(ibidir)/coreutils-$(coreutils-version)
+
+        # Download the tarball.
+	tarball=binutils-$(binutils-version).tar.lz
+	$(call import-source, $(binutils-url), $(binutils-checksum))
+
+        # Binutils' assembler (`as') and linker (`ld') will conflict with
+        # other compilers. So if we don't build our own compiler, we'll use
+        # the host opertating system's equivalents by just making links.
+	if [ x$(on_mac_os) = xyes ]; then
+	  $(call makelink,as)
+	  $(call makelink,ar)
+	  $(call makelink,ld)
+	  $(call makelink,nm)
+	  $(call makelink,ps)
+	  $(call makelink,ranlib)
+	  echo "" > $@
+	else
+
+          # Build binutils with the standard 'gbuild' function.
 	  $(call gbuild, binutils-$(binutils-version), static, \
 	                 --with-lib-path=$(sys_library_path), \
-	                 -j$(numthreads) ) \
-	  && if ! [ x"$(sys_library_path)" = x ]; then \
-	       for f in $(sys_library_path)/*crt*.o; do \
-	         b=$$($(ibdir)/basename $$f); \
-	         ln -s $$f $(ildir)/$$b; \
-	       done; \
-	     fi \
-	  && echo "GNU Binutils $(binutils-version)" > $@; \
+	                 -j$(numthreads) )
+
+          # The `ld' linker of Binutils needs several `*crt*.o' file to
+          # run. On some systems these object files aren't installed in
+          # standard places. We defined `LIBRARY_PATH' and that fixed the
+          # problem for many systems. However, some software (for example
+          # ImageMagick) over-write `LIBRARY_PATH', therefore there is no
+          # other way than to put a link to these necessary files in our
+          # local build directory. IMPORTANT NOTE: later, when we build the
+          # GNU C Library in the project, we should remove this step.
+	  if ! [ x"$(sys_library_path)" = x ]; then
+	    for f in $(sys_library_path)/*crt*.o; do
+	      b=$$($(ibdir)/basename $$f)
+	      ln -s $$f $(ildir)/$$b
+	    done
+	  fi
+
+          # Write the final target.
+	  echo "GNU Binutils $(binutils-version)" > $@
 	fi
 
 # We are having issues with `libiberty' (part of GCC) on Mac. So for now,
@@ -1301,117 +1244,162 @@ $(ibidir)/binutils: $(ibidir)/sed \
 #
 # We are currently having problems installing GCC on macOS, so for the time
 # being, if the project is being run on a macOS, we'll just set a link.
-ifeq ($(host_cc),1)
-gcc-tarball =
-else
-gcc-tarball = $(tdir)/gcc-$(gcc-version).tar.xz
-endif
-$(ibidir)/gcc: $(gcc-tarball) \
-               $(ibidir)/binutils
+$(ibidir)/gcc-$(gcc-version): $(ibidir)/binutils-$(binutils-version)
+
+        # Function to let the users know what to do if build fails.
+	error_message() {
+	    echo; echo
+	    echo "_________________________________________________"
+	    echo "!!!!!!!!       Warning from Maneage      !!!!!!!!"
+	    echo
+	    echo "Unfortunately building of GCC failed on this system!"
+	    echo "Can you please copy the last ~500 lines above and post it"
+	    echo "as a bug here (as an attached file):"
+	    echo "  https://sv.nongnu.org/support/?func=additem&group=reproduce"
+	    echo
+	    echo "In the meantime, please re-configure Maneage with '--host-cc'"
+	    echo "like below so it uses your own C compiler for building the"
+	    echo "high-level software ('-e' is to use the existing configuration):"
+	    echo
+	    echo "  ./project configure -e --host-cc"
+	    echo
+	    echo "__________ SEE NOTE FROM MANEAGE ABOVE __________"
+	    echo; exit 1
+	}
+
+        # Download the tarball.
+	tarball=gcc-$(gcc-version).tar.xz
+	$(call import-source, $(gcc-url), $(gcc-checksum))
 
         # GCC builds is own libraries in '$(idir)/lib64'. But all other
         # libraries are in '$(idir)/lib'. Since this project is only for a
         # single architecture, we can trick GCC into building its libraries
         # in '$(idir)/lib' by defining the '$(idir)/lib64' as a symbolic
         # link to '$(idir)/lib'.
-	if [ $(host_cc) = 1 ]; then \
-	  $(call makelink,cc); \
-	  $(call makelink,cc,,gcc); \
-	  $(call makelink,c++,,g++); \
-	  $(call makelink,gfortran); \
-	  $(call makelink,strip,mandatory); \
-	  ccinfo=$$(gcc --version | awk 'NR==1'); \
-	  echo "C compiler (""$$ccinfo"")" > $@; \
-	else \
-	  current_dir=$$(pwd); \
-	  rm -f $(ibdir)/gcc* $(ibdir)/g++ $(ibdir)/gfortran $(ibdir)/gcov*;\
-	  rm -rf $(ildir)/gcc $(ildir)/libcc* $(ildir)/libgcc*; \
-	  rm -rf $(ildir)/libgfortran* $(ildir)/libstdc* rm $(idir)/x86_64*;\
-	                                 \
-	  ln -fs $(ildir) $(idir)/lib64; \
-	                       \
+	if [ $(host_cc) = 1 ]; then
+
+          # Make sure we don't have any of the program we want to link to
+          # in the '.local/bin' directory.
+	  rm -f $(ibdir)/cc
+	  rm -f $(ibdir)/c++
+	  rm -f $(ibdir)/gcc
+	  rm -f $(ibdir)/cpp
+	  rm -f $(ibdir)/strip;
+	  rm -f $(ibdir)/gfortran;
+
+          # Put links to the host's tools in '.local/bin'.
+	  $(call makelink,cc)
+	  $(call makelink,cpp)
+	  $(call makelink,cc,,gcc)
+	  $(call makelink,gfortran)
+	  $(call makelink,c++,,g++)
+	  $(call makelink,strip,mandatory)
+	  ccinfo=$$(gcc --version | awk 'NR==1')
+	  echo "C compiler (""$$ccinfo"")" > $@
+
+	else
+
+          # We are building GCC, so to avoid any previous build in
+          # '.local/bin', we'll delete all the files that GCC builds from
+          # there.
+	  current_dir=$$(pwd)
+	  rm -f $(ibdir)/gcc* $(ibdir)/g++ $(ibdir)/gfortran $(ibdir)/gcov*
+	  rm -rf $(ildir)/gcc $(ildir)/libcc* $(ildir)/libgcc*
+	  rm -rf $(ildir)/libgfortran* $(ildir)/libstdc* rm $(idir)/x86_64*
+
+          # We don't want '.local/lib' and '.local/lib64' to be separate.
+	  ln -fs $(ildir) $(idir)/lib64
+
+          # By default we'll build GCC in the RAM to avoid building so many
+          # files and possibly harming the hard-drive or SSD. But if the
+          # RAM doesn't have enough space, we can't use it.
 	  in_ram=$$(df $(ddir) \
 	               | awk 'NR==2{print ($$4>10000000) ? "yes" : "no"}'); \
-	  if [ $$in_ram = "yes" ]; then odir=$(ddir); \
-	  else \
-	    odir=$(BDIR)/software/build-tmp-gcc; \
-	    if [ -d $$odir ]; then rm -rf $$odir; fi; \
-	    mkdir $$odir; \
-	  fi; \
-	  cd $$odir; \
-	  rm -rf gcc-$(gcc-version); \
-	  tar xf $(word 1,$(filter $(tdir)/%,$^)); \
-	  if [ $$odir != $(ddir) ]; then \
-	    ln -s $$odir/gcc-$(gcc-version) $(ddir)/gcc-$(gcc-version); \
-	  fi; \
-	  if cd gcc-$(gcc-version) \
-	  && mkdir build \
-	  && cd build \
-	  && ../configure SHELL=$(ibdir)/bash \
-	                  --prefix=$(idir) \
-	                  --with-mpc=$(idir) \
-	                  --with-gmp=$(idir) \
-	                  --with-isl=$(idir) \
-	                  --with-mpfr=$(idir) \
-	                  --with-local-prefix=$(idir) \
-	                  --with-build-time-tools=$(idir) \
-	                  --enable-lto \
-	                  --enable-shared \
-	                  --enable-cet=auto \
-	                  --enable-default-pie \
-	                  --enable-default-ssp \
-	                  --enable-decimal-float \
-	                  --enable-threads=posix \
-	                  --enable-languages=c,c++,fortran,objc,obj-c++ \
-	                  --disable-nls \
-	                  --disable-libada \
-	                  --disable-multilib \
-	                  --disable-multiarch \
-	  && make SHELL=$(ibdir)/bash -j$(numthreads) \
-	  && make SHELL=$(ibdir)/bash install \
-	  && cd ../.. \
-	  && tempname=$$odir/gcc-$(gcc-version)/build/rpath-temp-copy \
-	  && if [ "x$(on_mac_os)" != xyes ]; then \
-	       for f in $$(find $(idir)/libexec/gcc) $(ildir)/libstdc++*; do \
-	         isdynamic=$$(file $$f | grep "dynamically linked"); \
-	         if [ x"$$isdynamic" != x ]; then \
-	           cp $$f $$tempname; \
-	           patchelf --set-rpath $(ildir) $$tempname; \
-	           echo "$$f: added rpath"; \
-	           islibcpp=$$(echo $$f | grep "libstdc++"); \
-	           if [ x"$$islibcpp" != x ]; then \
-	             patchelf --add-needed $(ildir)/libiconv.so $$tempname; \
-	             echo "$$f: linked with libiconv"; \
-	           fi; \
-	           mv $$tempname $$f; \
-	         fi; \
-	       done; \
-	     fi \
-	  && rm -rf gcc-$(gcc-version) \
-	  && cd $$current_dir \
-	  && if [ "$$odir" != "$(ddir)" ]; then \
-	       rm -rf $$odir; \
-	       rm $(ddir)/gcc-$(gcc-version); \
-	     fi \
-	  && ln -sf $(ibdir)/gcc $(ibdir)/cc; \
-	  then \
-	    echo "GNU Compiler Collection (GCC) $(gcc-version)" > $@; \
-	  else echo; echo; echo; \
-	    echo "_________________________________________________"; \
-	    echo "!!!!!!!!       Warning from Maneage      !!!!!!!!"; \
-	    echo; \
-	    echo "Unfortunately building of GCC failed on this system!"; \
-	    echo "Can you please copy the last ~500 lines above and post it"; \
-	    echo "as a bug here (as an attached file):"; \
-	    echo "  https://sv.nongnu.org/support/?func=additem&group=reproduce"; \
-	    echo; \
-	    echo "In the meantime, please re-configure Maneage with '--host-cc'"; \
-	    echo "like below so it uses your own C compiler for building the"; \
-	    echo "high-level software ('-e' is to use the existing configuration):"; \
-	    echo; \
-	    echo "  ./project configure -e --host-cc"; \
-	    echo; \
-	    echo "__________ SEE NOTE FROM MANEAGE ABOVE __________"; \
-	    echo; exit 1; \
-	  fi; \
+	  if [ $$in_ram = "yes" ]; then odir=$(ddir)
+	  else
+	    odir=$(BDIR)/software/build-tmp-gcc
+	    if [ -d $$odir ]; then rm -rf $$odir; fi
+	    mkdir $$odir
+	  fi
+
+          # Go into the proper directory, unpack GCC and prepare the
+          # 'build' directory inside it for all the built files.
+	  cd $$odir
+	  rm -rf gcc-$(gcc-version)
+	  tar xf $(tdir)/$$tarball
+	  if [ $$odir != $(ddir) ]; then
+	    ln -s $$odir/gcc-$(gcc-version) $(ddir)/gcc-$(gcc-version)
+	  fi
+	  cd gcc-$(gcc-version)
+	  mkdir build
+	  cd build
+
+          # Configure, build and install GCC, if any of three steps fails,
+          # the error message will be printed.
+	  if ! ../configure SHELL=$(ibdir)/bash \
+	                    --prefix=$(idir) \
+	                    --with-mpc=$(idir) \
+	                    --with-gmp=$(idir) \
+	                    --with-isl=$(idir) \
+	                    --with-mpfr=$(idir) \
+	                    --with-local-prefix=$(idir) \
+	                    --with-build-time-tools=$(idir) \
+	                    --enable-lto \
+	                    --enable-shared \
+	                    --enable-cet=auto \
+	                    --enable-default-pie \
+	                    --enable-default-ssp \
+	                    --enable-decimal-float \
+	                    --enable-threads=posix \
+	                    --enable-languages=c,c++,fortran,objc,obj-c++ \
+	                    --disable-nls \
+	                    --disable-libada \
+	                    --disable-multilib \
+	                    --disable-multiarch; then error_message; fi
+	  if ! make SHELL=$(ibdir)/bash -j$(numthreads); then error_message; fi
+	  if ! make SHELL=$(ibdir)/bash install; then error_message; fi
+
+          # We need to manually fix the RPATH inside GCC's libraries, the
+          # programs built by GCC already have RPATH.
+	  tempname=$$odir/gcc-$(gcc-version)/build/rpath-temp-copy
+	  if [ -f $(ibdir)/patchelf ]; then
+
+            # Go over all the installed GCC libraries (its executables are
+            # fine!).
+	    for f in $$(find $(idir)/libexec/gcc -type f) $(ildir)/libstdc++*; do
+
+              # Make sure this is a static library, copy it to a temporary
+              # name (to avoid any possible usage of the file while it is
+              # being corrected), and add RPATH inside of it and put the
+              # corrected file back in its place. In the case of the
+              # standard C++ library, we also need to manually insert a
+              # linking to libiconv.
+	      if file $$f | grep -q "dynamically linked"; then
+	        cp $$f $$tempname
+	        patchelf --set-rpath $(ildir) $$tempname
+	        echo "$$f: added rpath"
+	        if echo $$f | grep -q "libstdc++"; then
+	          patchelf --add-needed $(ildir)/libiconv.so $$tempname
+	          echo "$$f: linked with libiconv"
+	        fi
+	        mv $$tempname $$f
+	      fi
+	    done
+	  fi
+
+          # Come back up to the un-packing directory and delete the GCC
+          # source directory.
+	  cd ../..
+	  rm -rf gcc-$(gcc-version)
+	  cd $$current_dir
+	  if [ "$$odir" != "$(ddir)" ]; then
+	    rm -rf $$odir;
+	    rm $(ddir)/gcc-$(gcc-version);
+	  fi
+
+          # Set 'cc' to point to 'gcc'.
+	  ln -sf $(ibdir)/gcc $(ibdir)/cc
+
+          # Write the final target.
+	  echo "GNU Compiler Collection (GCC) $(gcc-version)" > $@
 	fi
diff --git a/reproduce/software/make/build-rules.mk b/reproduce/software/make/build-rules.mk
index 260ded8..7471e5b 100644
--- a/reproduce/software/make/build-rules.mk
+++ b/reproduce/software/make/build-rules.mk
@@ -1,7 +1,7 @@
 # Generic configurable recipes to build packages with GNU Build system or
 # CMake. This is Makefile is not intended to be run directly, it will be
-# imported into `basic.mk' and `high-level.mk'. They should be activated
-# with Make's `Call' function.
+# imported into 'basic.mk' and 'high-level.mk'. They should be activated
+# with Make's 'Call' function.
 #
 # Copyright (C) 2018-2020 Mohammad Akhlaghi <mohammad@akhlaghi.org>
 #
@@ -22,31 +22,84 @@
 
 
 
-# IMPORTANT note
-# --------------
+# Import/download project's source
+# --------------------------------
 #
-# Without using `&&', if a step fails, the process will continue. However,
-# in the `if' statements, we need `;' (particularly between `]' and
-# `then'). So we need to put any necessary checks at the start, then when
-# we start the process, every command will be separated by an `&&'.
+# Copy/Download the raw tarball into an '.unchecked' suffix. Then calculate
+# its checksum and if it is correct, remove the extra suffix.
+#
+# Arguments:
+#   1: The optional URL to use for this tarball.
+#   2: The expeced checksum of the tarball.
+#
+# Necessary shell variables
+#   'tarball': This is the name of the actual tarball file without a
+#   directory.
+import-source = final=$(tdir)/$$tarball; \
+	url=$(strip $(1)); \
+	exp_checksum="$(strip $(2))"; \
+	if [ -f $$final ]; then \
+	  echo "$(tdir)/$$tarball: already present in project."; \
+	else \
+	  unchecked="$$final.unchecked"; \
+	  rm -f "$$unchecked"; \
+	  if [ -f $(DEPENDENCIES-DIR)/$$tarball ]; then \
+	    cp $(DEPENDENCIES-DIR)/$$tarball "$$unchecked"; \
+	  else \
+	    if [ x"$$url" = x ]; then \
+	      bservers="$(backupservers)"; \
+	      tarballurl=$(topbackupserver)/$$tarball; \
+	    else \
+	      bservers="$(backupservers_all)"; \
+	      tarballurl=$$url/$$tarball; \
+	    fi; \
+	    if [ -f $(ibdir)/wget ]; then \
+	      downloader="wget --no-use-server-timestamps -O"; \
+	    else \
+	      downloader="$(DOWNLOADER)"; \
+	    fi; \
+	    touch $(lockdir)/download; \
+	    $(downloadwrapper) "$$downloader" $(lockdir)/download \
+	                       $$tarballurl "$$unchecked" "$$bservers"; \
+	  fi; \
+	  if [ x"$$exp_checksum" = x"NO-CHECK-SUM" ]; then \
+	    mv "$$unchecked" "$$final"; \
+	  else \
+	    if type sha512sum > /dev/null 2>/dev/null; then \
+	      checksum=$$(sha512sum "$$unchecked" | awk '{print $$1}'); \
+	      if [ x"$$checksum" = x"$$exp_checksum" ]; then \
+	        mv "$$unchecked" "$$final"; \
+	      else \
+	        echo "ERROR: Non-matching checksum for '$$tarball'."; \
+	        echo "Checksum should be: $$exp_checksum"; \
+	        echo "Checksum is:        $$checksum"; \
+	        exit 1; \
+	      fi; \
+	    else mv "$$unchecked" "$$final"; \
+	    fi; \
+	  fi; \
+	fi
 
 
 
 
 
+# Unpack a tarball
+# ----------------
+#
 # Unpack a tarball in the current directory. The issue is that until we
 # install GNU Tar within Maneage, we have to use the host's Tar
 # implementation and in some cases, they don't recognize '.lz'.
-uncompress = csuffix=$$(echo $$tarball \
+uncompress = csuffix=$$(echo $$utarball \
 	                     | sed -e's/\./ /g' \
 	                     | awk '{print $$NF}'); \
 	if [ x$$csuffix = xlz ]; then \
 	  intarrm=1; \
-	  intar=$$(echo $$tarball | sed -e's/.lz//'); \
-	  lzip -c -d $$tarball > $$intar; \
+	  intar=$$(echo $$utarball | sed -e's/.lz//'); \
+	  lzip -c -d $$utarball > $$intar; \
 	else \
 	  intarrm=0; \
-	  intar=$$tarball; \
+	  intar=$$utarball; \
 	fi; \
 	if tar xf $$intar; then \
 	  if [ x$$intarrm = x1 ]; then rm $$intar; fi; \
@@ -64,20 +117,20 @@ uncompress = csuffix=$$(echo $$tarball \
 #
 # Arguments:
 #  1: Directory name after unpacking.
-#  2: Set to `static' for a static build.
+#  2: Set to 'static' for a static build.
 #  3: Extra configuration options.
 #  4: Extra options/arguments to pass to Make.
-#  5: Step to run between `make' and `make install': usually `make check'.
-#  6: The configuration script (`configure' by default).
-#  7: Arguments for `make install'.
+#  5: Step to run between 'make' and 'make install': usually 'make check'.
+#  6: The configuration script ('configure' by default).
+#  7: Arguments for 'make install'.
 #
-# NOTE: Unfortunately the configure script of `zlib' doesn't recognize
-# `SHELL'. So we'll have to remove it from the call to the configure
+# NOTE: Unfortunately the configure script of 'zlib' doesn't recognize
+# 'SHELL'. So we'll have to remove it from the call to the configure
 # script.
 #
 # NOTE: A program might not contain any configure script. In this case,
-# we'll just pass a non-relevant function like `pwd'. So SED should be used
-# to modify `confscript' or to set `configop'.
+# we'll just pass a non-relevant function like 'pwd'. So SED should be used
+# to modify 'confscript' or to set 'configop'.
 gbuild = if [ x$(static_build) = xyes ] && [ "x$(2)" = xstatic ]; then \
 	   export LDFLAGS="$$LDFLAGS -static"; \
 	 fi; \
@@ -85,9 +138,8 @@ gbuild = if [ x$(static_build) = xyes ] && [ "x$(2)" = xstatic ]; then \
 	 if [ x"$$check" = x ]; then check="echo Skipping-check"; fi; \
 	 cd $(ddir); \
 	 rm -rf $(1); \
-	 if [ x"$$gbuild_tar" = x ]; then \
-	   tarball=$(word 1,$(filter $(tdir)/%,$^)); \
-	 else tarball=$$gbuild_tar; \
+	 if [ x"$$gbuild_tar" = x ]; then utarball=$(tdir)/$$tarball; \
+	 else                             utarball=$$gbuild_tar;      \
 	 fi; \
 	 $(call uncompress); \
 	 cd $(1); \
@@ -95,7 +147,7 @@ gbuild = if [ x$(static_build) = xyes ] && [ "x$(2)" = xstatic ]; then \
 	 if   [ x"$(strip $(6))" = x ]; then confscript=./configure; \
 	 else confscript="$(strip $(6))"; \
 	 fi; \
-             \
+	     \
 	 if   [ -f $(ibdir)/bash ]; then \
 	   if [ -f "$$confscript" ]; then \
 	     sed -e's|\#\! /bin/sh|\#\! $(ibdir)/bash|' \
@@ -108,7 +160,7 @@ gbuild = if [ x$(static_build) = xyes ] && [ "x$(2)" = xstatic ]; then \
 	 elif [ -f /bin/bash ]; then shellop="SHELL=/bin/bash"; \
 	 else shellop="SHELL=/bin/sh"; \
 	 fi; \
-             \
+	     \
 	 if [ -f "$$confscript" ]; then \
 	   if [ x"$(strip $(1))" = x"zlib-$(zlib-version)" ]; then \
 	     configop="--prefix=$(idir)"; \
@@ -118,12 +170,12 @@ gbuild = if [ x$(static_build) = xyes ] && [ "x$(2)" = xstatic ]; then \
 	     \
 	 echo; echo "Using '$$confscript' to configure:"; echo; \
 	 echo "$$confscript $(3) $$configop"; echo; \
-	 $$confscript $(3) $$configop \
-	 && make "$$shellop" $(4) \
-	 && $$check \
-	 && make "$$shellop" install $(7) \
-	 && cd .. \
-	 && rm -rf $(1)
+	 $$confscript $(3) $$configop; \
+	 make "$$shellop" $(4); \
+	 $$check; \
+	 make "$$shellop" install $(7); \
+	 cd ..; \
+	 rm -rf $(1)
 
 
 
@@ -131,7 +183,7 @@ gbuild = if [ x$(static_build) = xyes ] && [ "x$(2)" = xstatic ]; then \
 # CMake
 # -----
 #
-# According to the link below, in CMake `/bin/sh' is hardcoded, so there is
+# According to the link below, in CMake '/bin/sh' is hardcoded, so there is
 # no way to change it unfortunately!
 #
 # https://stackoverflow.com/questions/21167014/how-to-set-shell-variable-in-makefiles-generated-by-cmake
@@ -139,17 +191,18 @@ cbuild = if [ x$(static_build) = xyes ] && [ $(2)x = staticx ]; then \
 	   export LDFLAGS="$$LDFLAGS -static"; \
 	   opts="-DBUILD_SHARED_LIBS=OFF"; \
 	 fi; \
-	 tarball=$(word 1,$(filter $(tdir)/%,$^)); \
 	 cd $(ddir); \
 	 rm -rf $(1); \
+	 utarball=$(tdir)/$$tarball; \
 	 $(call uncompress); \
-	 cd $(1) \
-	 && rm -rf project-build \
-	 && mkdir project-build \
-	 && cd project-build \
-	 && cmake .. -DCMAKE_LIBRARY_PATH=$(ildir) \
-	             -DCMAKE_INSTALL_PREFIX=$(idir) \
-	             -DCMAKE_VERBOSE_MAKEFILE:BOOL=ON $$opts $(3) \
-	 && make && make install \
-	 && cd ../.. \
-	 && rm -rf $(1)
+	 cd $(1); \
+	 rm -rf project-build; \
+	 mkdir project-build; \
+	 cd project-build; \
+	 cmake .. -DCMAKE_LIBRARY_PATH=$(ildir) \
+	          -DCMAKE_INSTALL_PREFIX=$(idir) \
+	          -DCMAKE_VERBOSE_MAKEFILE:BOOL=ON $$opts $(3); \
+	 make; \
+	 make install; \
+	 cd ../..; \
+	 rm -rf $(1)
diff --git a/reproduce/software/make/high-level.mk b/reproduce/software/make/high-level.mk
index 75fa8ac..b756cb9 100644
--- a/reproduce/software/make/high-level.mk
+++ b/reproduce/software/make/high-level.mk
@@ -4,7 +4,11 @@
 #                      !!!!! IMPORTANT NOTES !!!!!
 #
 # This Makefile will be run by the initial `./project configure' script. It
-# is not included into the reproduction pipe after that.
+# is not included into the project afterwards.
+#
+# This Makefile builds the high-level (optional) software in Maneage that
+# users can choose for different projects. It thus assumes that the
+# low-level tools (like GNU Tar and etc) are already build by 'basic.mk'.
 #
 # ------------------------------------------------------------------------
 #
@@ -24,35 +28,82 @@
 # You should have received a copy of the GNU General Public License
 # along with this Makefile.  If not, see <http://www.gnu.org/licenses/>.
 
-
-
-# Top level environment
+# Top level environment (same as 'basic.mk')
 include reproduce/software/config/LOCAL.conf
 include reproduce/software/make/build-rules.mk
-include reproduce/software/config/TARGETS.conf
 include reproduce/software/config/versions.conf
 include reproduce/software/config/checksums.conf
+
+# The optional URLs of software. Note that these may need the software
+# version, so it is important that they be loaded after 'versions.conf'.
+include reproduce/software/config/urls.conf
+
+# Configurations specific to this Makefile
+include reproduce/software/config/TARGETS.conf
 include reproduce/software/config/texlive-packages.conf
 
+# Basic directories (similar to 'basic.mk').
 lockdir = $(BDIR)/locks
 tdir    = $(BDIR)/software/tarballs
 ddir    = $(BDIR)/software/build-tmp
 idir    = $(BDIR)/software/installed
 ibdir   = $(BDIR)/software/installed/bin
 ildir   = $(BDIR)/software/installed/lib
-iidir   = $(BDIR)/software/installed/include
-dtexdir = $(shell pwd)/reproduce/software/bibtex
-patchdir= $(shell pwd)/reproduce/software/patches
-itidir  = $(BDIR)/software/installed/version-info/tex
-ictdir  = $(BDIR)/software/installed/version-info/cite
-ipydir  = $(BDIR)/software/installed/version-info/python
 ibidir  = $(BDIR)/software/installed/version-info/proglib
 
-# Set the top-level software to build.
-all: $(foreach p, $(top-level-programs),  $(ibidir)/$(p)) \
-     $(foreach p, $(top-level-python),    $(ipydir)/$(p)) \
+# Basic directories (specific to this Makefile).
+iidir    = $(BDIR)/software/installed/include
+shsrcdir = $(shell pwd)/reproduce/software/shell
+dtexdir  = $(shell pwd)/reproduce/software/bibtex
+patchdir = $(shell pwd)/reproduce/software/patches
+itidir   = $(BDIR)/software/installed/version-info/tex
+ictdir   = $(BDIR)/software/installed/version-info/cite
+ipydir   = $(BDIR)/software/installed/version-info/python
+
+# Targets to build.
+ifeq ($(strip $(all_highlevel)),1)
+
+  # Set it to build all programs. Pay attention to special software:
+  #
+  # Versions as variables (for example minizip): they have the same as the
+  # version as others and the version number is actually a variable. So
+  # we'll need to filter it out, then add it in the end: minizip (has same
+  # version as zlib)
+  #
+  # Packages that are installed in the same recipe as others. These need to
+  # be totally removed when testing all the builds (they will be built
+  # anyway).  lapack (installed with ATLAS)
+  targets-proglib := $(filter-out minizip-% lapack-%, \
+      $(shell awk '/^# CLASS:PYTHON/{good=0} \
+                   good==1 && !/^#/ && $$1 ~ /-version$$/ { \
+                       printf("%s %s ", $$1, $$3)} \
+                   /^# CLASS:HIGHLEVEL/{good=1}' \
+                  reproduce/software/config/versions.conf \
+              | sed 's/version //g')) \
+      minizip-$(minizip-version)
+
+  # List all existing Python packages.
+  targets-python := $(shell \
+    awk '/^# CLASS:PYTHON/{good=1} \
+         good==1 && !/^#/ && $$1 ~ /-version$$/ {printf("%s %s ",$$1,$$3)}' \
+        reproduce/software/config/versions.conf | sed 's/version //g')
+else
+
+  # Append the version of each software to its name. We are using a Make
+  # feature where a variable name is defined with another variable.
+  targets-python := $(foreach p,$(top-level-python),$(p)-$($(p)-version))
+  targets-proglib := $(foreach p,$(top-level-programs),$(p)-$($(p)-version))
+
+endif
+
+# Ultimate Makefile target.
+all: $(foreach p, $(targets-proglib), $(ibidir)/$(p)) \
+     $(foreach p, $(targets-python), $(ipydir)/$(p)) \
      $(itidir)/texlive
 
+# Define the shell environment
+# ----------------------------
+#
 # Other basic environment settings: We are only including the host
 # operating system's PATH environment variable (after our own!) for the
 # compiler and linker. For the library binaries and headers, we are only
@@ -67,18 +118,28 @@ all: $(foreach p, $(top-level-programs),  $(ibidir)/$(p)) \
 #
 #    2) Add `--noprofile --norc' to `.SHELLFLAGS' so doesn't load the
 #       user's environment.
+#
+# Shell settings similar to 'basic.mk':
 .ONESHELL:
-.SHELLFLAGS := --noprofile --norc -ec
-export CCACHE_DISABLE := 1
 export PATH := $(ibdir)
+export CCACHE_DISABLE := 1
+export SHELL := $(ibdir)/bash
+export CPPFLAGS := -I$(idir)/include
+.SHELLFLAGS := --noprofile --norc -ec
+export PKG_CONFIG_PATH := $(ildir)/pkgconfig
+export LDFLAGS := $(rpath_command) -L$(ildir)
+export PKG_CONFIG_LIBDIR := $(ildir)/pkgconfig
+
+# Settings specific to this Makefile.
 export CC := $(ibdir)/gcc
 export CXX := $(ibdir)/g++
-export SHELL := $(ibdir)/bash
 export F77 := $(ibdir)/gfortran
 export LD_RUN_PATH := $(ildir):$(il64dir)
-export PKG_CONFIG_PATH := $(ildir)/pkgconfig
 export LD_LIBRARY_PATH := $(ildir):$(il64dir)
-export PKG_CONFIG_LIBDIR := $(ildir)/pkgconfig
+
+# Recipe startup script, see `reproduce/software/shell/bashrc.sh'.
+export PROJECT_STATUS := configure_highlevel
+export BASH_ENV := $(shell pwd)/reproduce/software/shell/bashrc.sh
 
 # Until we build our own C library, without this, our GCC won't be able to
 # compile anything! Note that on most systems (in particular
@@ -97,282 +158,45 @@ export DYLD_LIBRARY_PATH :=
 # for `ld'.
 export LIBRARY_PATH := $(sys_library_path)
 
-# Recipe startup script, see `reproduce/software/shell/bashrc.sh'.
-export PROJECT_STATUS := configure_highlevel
-export BASH_ENV := $(shell pwd)/reproduce/software/shell/bashrc.sh
-
-# Servers to use as backup, later this should go in a file that is not
-# under version control (the actual server that the tarbal comes from is
-# irrelevant).
-backupservers := $(shell awk '!/^#/{printf "%s ", $$1}' \
-                         reproduce/software/config/servers-backup.conf)
-
 # Building flags:
 #
 # C++ flags: when we build GCC, the C++ standard library needs to link with
 # libiconv. So it is necessary to generically include `-liconv' for all C++
 # builds.
-export CPPFLAGS          := -I$(idir)/include
-export LDFLAGS           := $(rpath_command) -L$(ildir)
 ifeq ($(host_cc),0)
 export CXXFLAGS          := -liconv
 endif
 
-
-
-
-
-# We want the download to happen on a single thread. So we need to define a
-# lock, and call a special script we have written for this job. These are
-# placed here because we want them both in the `high-level.mk' and
-# `python.mk'.
-$(lockdir): | $(BDIR); mkdir $@
-downloader="wget --no-use-server-timestamps -O";
+# Servers to use as backup. Maneage already has some fixed servers that can
+# be used to download software tarballs. They are in a configuation
+# file. But we give precedence to the "user" backup servers.
+#
+# One important "user" server (which the user doesn't actually give, but is
+# found at configuration time in 'configure.sh') is Zenodo (see the
+# description in 'configure.sh' for more on why this depends on
+# configuration time).
+#
+# Afer putting everything together, we use the first server as the
+# reference for all software if their '-url' variable isn't defined (in
+# 'reproduce/software/config/urls.conf').
 downloadwrapper = ./reproduce/analysis/bash/download-multi-try
+maneage_backup_urls := $(shell awk '!/^#/{printf "%s ", $$1}' \
+                               reproduce/software/config/servers-backup.conf)
+backupservers_all = $(user_backup_urls) $(maneage_backup_urls)
+topbackupserver = $(word 1, $(backupservers_all))
+backupservers = $(filter-out $(topbackupserver),$(backupservers_all))
 
 
 
 
 
-# Mini-environment software
+# Import rules to build Python packages,
 include reproduce/software/make/python.mk
 
 
 
 
 
-# Tarballs
-# --------
-#
-# All the necessary tarballs are defined and prepared with this rule.
-#
-# Note that we want the tarballs to follow the convention of NAME-VERSION
-# before the `tar.XX' prefix. For those programs that don't follow this
-# convention, but include the name/version in their tarball names with
-# another format, we'll do the modification before the download so the
-# downloaded file has our desired format.
-tarballs = $(foreach t, apachelog4cxx-$(apachelog4cxx-version).tar.lz \
-                        apr-$(apr-version).tar.gz \
-                        apr-util-$(apr-util-version).tar.gz \
-                        astrometry.net-$(astrometrynet-version).tar.gz \
-                        atlas-$(atlas-version).tar.bz2 \
-                        autoconf-$(autoconf-version).tar.lz \
-                        automake-$(automake-version).tar.gz \
-                        bison-$(bison-version).tar.xz \
-                        boost-$(boost-version).tar.gz \
-                        cairo-$(cairo-version).tar.xz \
-                        cdsclient-$(cdsclient-version).tar.gz \
-                        cfitsio-$(cfitsio-version).tar.gz \
-                        cmake-$(cmake-version).tar.gz \
-                        eigen-$(eigen-version).tar.gz \
-                        expat-$(expat-version).tar.lz \
-                        fftw-$(fftw-version).tar.gz \
-                        flex-$(flex-version).tar.gz \
-                        freetype-$(freetype-version).tar.gz \
-                        gdb-$(gdb-version).tar.gz \
-                        ghostscript-$(ghostscript-version).tar.gz \
-                        gnuastro-$(gnuastro-version).tar.lz \
-                        gsl-$(gsl-version).tar.gz \
-                        hdf5-$(hdf5-version).tar.gz \
-                        healpix-$(healpix-version).tar.gz \
-                        help2man-$(help2man-version).tar.xz \
-                        imagemagick-$(imagemagick-version).tar.xz \
-                        imfit-$(imfit-version).tar.gz \
-                        install-tl-unx.tar.gz \
-                        jpegsrc.$(libjpeg-version).tar.gz \
-                        lapack-$(lapack-version).tar.gz \
-                        libgit2-$(libgit2-version).tar.gz \
-                        libnsl-$(libnsl-version).tar.gz \
-                        libpng-$(libpng-version).tar.xz \
-                        libtirpc-$(libtirpc-version).tar.bz2 \
-                        missfits-$(missfits-version).tar.gz \
-                        netpbm-$(netpbm-version).tar.gz \
-                        openblas-$(openblas-version).tar.gz \
-                        openmpi-$(openmpi-version).tar.gz \
-                        openssh-$(openssh-version).tar.gz \
-                        patch-$(patch-version).tar.gz \
-                        pixman-$(pixman-version).tar.gz \
-                        R-$(R-version).tar.gz \
-                        scamp-$(scamp-version).tar.lz \
-                        scons-$(scons-version).tar.gz \
-                        sextractor-$(sextractor-version).tar.lz \
-                        swarp-$(swarp-version).tar.gz \
-                        swig-$(swig-version).tar.gz \
-                        rpcsvc-proto-$(rpcsvc-proto-version).tar.xz \
-                        tides-$(tides-version).tar.gz \
-                        tiff-$(libtiff-version).tar.gz \
-                        valgrind-$(valgrind-version).tar.bz2 \
-                        wcslib-$(wcslib-version).tar.bz2 \
-                        xlsxio-$(xlsxio-version).tar.gz \
-                        yaml-$(yaml-version).tar.gz \
-                        zlib-$(zlib-version).tar.gz \
-                      , $(tdir)/$(t) )
-$(tarballs): $(tdir)/%: | $(lockdir)
-
-        # Remove the version numbers and suffix from the tarball name so we
-        # can search more easily only with the program name. This requires
-        # the first character of the version to be a digit: packages such
-        # as `foo' and `foo-3' will not be distinguished, but `foo' and
-        # `foo2' will be distinguished.
-	@n=$$(echo $* | sed -e's/-[0-9]/ /' -e's/\./ /g' \
-	              | awk '{print $$1}' )
-
-        # Set the top download link of the requested tarball.
-	mergenames=1
-	if   [ $$n = apachelog4cxx ]; then c=$(apachelog4cxx-checksum); w=http://akhlaghi.org/maneage-software
-	elif [ $$n = apr         ]; then c=$(apr-checksum); w=https://www-us.apache.org/dist/apr
-	elif [ $$n = apr-util    ]; then c=$(apr-util-checksum); w=https://www-us.apache.org/dist/apr
-	elif [ $$n = astrometry  ]; then c=$(astrometrynet-checksum); w=http://astrometry.net/downloads
-	elif [ $$n = atlas       ]; then
-	  mergenames=0
-	  c=$(atlas-checksum)
-	  w=https://sourceforge.net/projects/math-atlas/files/Stable/$(atlas-version)/atlas$(atlas-version).tar.bz2/download
-	elif [ $$n = autoconf    ]; then c=$(autoconf-checksum); w=http://akhlaghi.org/maneage-software
-	elif [ $$n = automake    ]; then c=$(automake-checksum); w=http://ftp.gnu.org/gnu/automake
-	elif [ $$n = bison       ]; then c=$(bison-checksum); w=http://ftp.gnu.org/gnu/bison
-	elif [ $$n = boost       ]; then
-	  mergenames=0
-	  c=$(boost-checksum)
-	  vstr=$$(echo $(boost-version) | sed -e's/\./_/g')
-	  w=https://dl.bintray.com/boostorg/release/$(boost-version)/source/boost_$$vstr.tar.gz
-	elif [ $$n = cairo       ]; then c=$(cairo-checksum); w=https://www.cairographics.org/releases
-	elif [ $$n = cdsclient   ]; then c=$(cdsclient-checksum); w=http://cdsarc.u-strasbg.fr/ftp/pub/sw
-	elif [ $$n = cfitsio     ]; then c=$(cfitsio-checksum); w=https://heasarc.gsfc.nasa.gov/FTP/software/fitsio/c
-	elif [ $$n = cmake       ]; then
-	  mergenames=0
-	  c=$(cmake-checksum)
-	  majv=$$(echo $(cmake-version) \
-	               | sed -e's/\./ /' \
-	               | awk '{printf("%d.%d", $$1, $$2)}')
-	  w=https://cmake.org/files/v$$majv/cmake-$(cmake-version).tar.gz
-	elif [ $$n = eigen       ]; then
-	  mergenames=0
-	  c=$(eigen-checksum);
-	  w=http://bitbucket.org/eigen/eigen/get/$(eigen-version).tar.gz
-	elif [ $$n = expat    ]; then
-	  mergenames=0
-	  c=$(expat-checksum)
-	  vstr=$$(echo $(expat-version) | sed -e's/\./_/g')
-	  w=https://github.com/libexpat/libexpat/releases/download/R_$$vstr/expat-$(expat-version).tar.lz
-	elif [ $$n = fftw        ]; then c=$(fftw-checksum); w=ftp://ftp.fftw.org/pub/fftw
-	elif [ $$n = flex        ]; then c=$(flex-checksum); w=https://github.com/westes/flex/files/981163
-	elif [ $$n = freetype    ]; then c=$(freetype-checksum); w=https://download.savannah.gnu.org/releases/freetype
-	elif [ $$n = gdb         ]; then c=$(gdb-checksum); w=http://ftp.gnu.org/gnu/gdb
-	elif [ $$n = ghostscript ]; then
-	  c=$(ghostscript-checksum)
-	  v=$$(echo $(ghostscript-version) | sed -e's/\.//')
-	  w=https://github.com/ArtifexSoftware/ghostpdl-downloads/releases/download/gs$$v
-	elif [ $$n = gnuastro    ]; then c=$(gnuastro-checksum); w=http://ftp.gnu.org/gnu/gnuastro
-	elif [ $$n = gsl         ]; then c=$(gsl-checksum); w=http://ftp.gnu.org/gnu/gsl
-	elif [ $$n = hdf5        ]; then
-	  mergenames=0
-	  c=$(hdf5-checksum)
-	  majorver=$$(echo $(hdf5-version) | sed -e 's/\./ /g' | awk '{printf("%d.%d", $$1, $$2)}')
-	  w=https://support.hdfgroup.org/ftp/HDF5/releases/hdf5-$$majorver/hdf5-$(hdf5-version)/src/$*
-	elif [ $$n = healpix     ]; then c=$(healpix-checksum); w=http://akhlaghi.org/maneage-software
-	elif [ $$n = help2man    ]; then c=$(help2man-checksum); w=http://ftp.gnu.org/gnu/help2man
-	elif [ $$n = imagemagick ]; then c=$(imagemagick-checksum); w=http://akhlaghi.org/maneage-software
-	elif [ $$n = imfit       ]; then
-	  mergenames=0
-	  c=$(imfit-checksum)
-	  w=http://www.mpe.mpg.de/~erwin/resources/imfit/imfit-$(imfit-version)-source.tar.gz
-	elif [ $$n = install-tl-unx ]; then c=NO-CHECK-SUM; w=http://mirror.ctan.org/systems/texlive/tlnet
-	elif [ $$n = jpegsrc     ]; then c=$(libjpeg-checksum); w=http://ijg.org/files
-	elif [ $$n = lapack      ]; then c=$(lapack-checksum); w=http://www.netlib.org/lapack
-	elif [ $$n = libnsl      ]; then c=$(libnsl-checksum); w=http://akhlaghi.org/maneage-software
-	elif [ $$n = libpng      ]; then c=$(libpng-checksum); w=https://download.sourceforge.net/libpng
-	elif [ $$n = libgit2     ]; then
-	  mergenames=0
-	  c=$(libgit2-checksum)
-	  w=https://github.com/libgit2/libgit2/archive/v$(libgit2-version).tar.gz
-	elif [ $$n = libtirpc    ]; then c=$(libtirpc-checksum); w=https://downloads.sourceforge.net/libtirpc
-	elif [ $$n = missfits    ]; then c=$(missfits-checksum); w=https://www.astromatic.net/download/missfits
-	elif [ $$n = netpbm      ]; then c=$(netpbm-checksum); w=http://akhlaghi.org/maneage-software
-	elif [ $$n = openblas    ]; then
-	  mergenames=0
-	  c=$(openblas-checksum)
-	  w=https://github.com/xianyi/OpenBLAS/archive/v$(openblas-version).tar.gz
-	elif [ $$n = openmpi     ]; then
-	  mergenames=0
-	  c=$(openmpi-checksum)
-	  majorver=$$(echo $(openmpi-version) | sed -e 's/\./ /g' | awk '{printf("%d.%d", $$1, $$2)}')
-	  w=https://download.open-mpi.org/release/open-mpi/v$$majorver/$*
-	elif [ $$n = openssh     ]; then c=$(openssh-checksum); w=https://artfiles.org/openbsd/OpenSSH/portable
-	elif [ $$n = patch       ]; then c=$(patch-checksum); w=http://ftp.gnu.org/gnu/patch
-	elif [ $$n = pixman      ]; then c=$(pixman-checksum); w=https://www.cairographics.org/releases
-	elif [ $$n = R           ]; then c=$(R-checksum);
-	  majver=$$(echo $(R-version) | sed -e's/\./ /g' | awk '{print $$1}')
-	  w=https://cran.r-project.org/src/base/R-$$majver
-	elif [ $$n = rpcsvc-proto ]; then c=$(rpcsvc-proto-checksum); w=https://github.com/thkukuk/rpcsvc-proto/releases/download/v$(rpcsvc-proto-version)
-	elif [ $$n = scamp       ]; then c=$(scamp-checksum); w=http://akhlaghi.org/maneage-software
-	elif [ $$n = scons       ]; then
-	  mergenames=0
-	  c=$(scons-checksum)
-	  w=https://sourceforge.net/projects/scons/files/scons/$(scons-version)/scons-$(scons-version).tar.gz/download
-	elif [ $$n = sextractor  ]; then c=$(sextractor-checksum); w=http://akhlaghi.org/maneage-software
-	elif [ $$n = swarp       ]; then c=$(swarp-checksum); w=https://www.astromatic.net/download/swarp
-	elif [ $$n = swig        ]; then c=$(swig-checksum); w=https://sourceforge.net/projects/swig/files/swig/swig-$(swig-version)
-	elif [ $$n = tides       ]; then c=$(tides-checksum); w=http://akhlaghi.org/maneage-software
-	elif [ $$n = tiff        ]; then c=$(libtiff-checksum); w=https://download.osgeo.org/libtiff
-	elif [ $$n = valgrind    ]; then c=$(valgrind-checksum); w=https://sourceware.org/pub/valgrind
-	elif [ $$n = wcslib      ]; then c=$(wcslib-checksum); w=ftp://ftp.atnf.csiro.au/pub/software/wcslib
-	elif [ $$n = xlsxio      ]; then
-	  mergenames=0
-	  c=$(xlsxio-checksum);
-	  w=https://github.com/brechtsanders/xlsxio/archive/$(xlsxio-version).tar.gz
-	elif [ $$n = yaml        ]; then c=$(yaml-checksum); w=pyyaml.org/download/libyaml
-	elif [ $$n = zlib        ]; then c=$(zlib-checksum); w=https://zlib.net
-	else
-	  echo; echo; echo;
-	  echo "'$$n' not recognized as a software tarball name to download."
-	  echo; echo; echo;
-	  exit 1
-	fi
-
-        # Download the requested tarball. Note that some packages may not
-        # follow our naming convention (where the package name is merged
-        # with its version number). In such cases, `w' will be the full
-        # address, not just the top directory address. But since we are
-        # storing all the tarballs in one directory, we want it to have the
-        # same naming convention, so we'll download it to a temporary name,
-        # then rename that.
-	rm -f "$@.unchecked"
-	if [ -f $(DEPENDENCIES-DIR)/$* ]; then
-	  cp $(DEPENDENCIES-DIR)/$* "$@.unchecked"
-	else
-	  if [ $$mergenames = 1 ]; then  tarballurl=$$w/"$*"
-	  else                           tarballurl=$$w
-	  fi
-
-          # Download using the script specially defined for this job.
-	  touch $(lockdir)/download
-	  downloader="wget --no-use-server-timestamps -O"
-	  $(downloadwrapper) "$$downloader" $(lockdir)/download \
-	                     $$tarballurl "$@.unchecked" "$(backupservers)"
-	fi
-
-        # Make sure this is the expected tarball. Note that we now have a
-        # controlled `sha512sum' build (as part of GNU Coreutils). So we
-        # don't need to check its existance like `basic.mk'. But for LaTeX,
-        # we need to ignore a checksum (it downloads the binaries).
-	if [ x"$$c" == x"NO-CHECK-SUM" ]; then
-	  mv "$@.unchecked" "$@"
-	else
-	  checksum=$$(sha512sum "$@.unchecked" | awk '{print $$1}')
-	  if [ x"$$checksum" = x"$$c" ]; then
-	    mv "$@.unchecked" "$@"
-	  else
-	    echo "ERROR: Non-matching checksum for '$*'."
-	    echo "Checksum should be: $$c"
-	    echo "Checksum is:        $$checksum"
-	    exit 1
-	  fi
-	fi
-
-
-
-
-
 
 
 
@@ -409,39 +233,50 @@ $(tarballs): $(tdir)/%: | $(lockdir)
 # build it because it will complain about the version of libtool, so until
 # the version 0.11.0 of log4cxx, we'll have to run `autogen.sh' on the
 # unpacked source also.
-$(ibidir)/apachelog4cxx: $(ibidir)/automake \
-                         $(tdir)/apachelog4cxx-$(apachelog4cxx-version).tar.lz
-
+$(ibidir)/apachelog4cxx-$(apachelog4cxx-version): \
+                        $(ibidir)/expat-$(expat-version) \
+                        $(ibidir)/apr-util-$(apr-util-version) \
+                        $(ibidir)/automake-$(automake-version)
+	tarball=apachelog4cxx-$(apachelog4cxx-version).tar.lz
+	$(call import-source, $(apachelog4cxx-url), $(apachelog4cxx-checksum))
 	pdir=apachelog4cxx-$(apachelog4cxx-version)
 	rm -rf $(ddir)/$$pdir
 	topdir=$(pwd)
 	cd $(ddir)
-	tar xf $(word 1,$(filter $(tdir)/%,$^))
+	tar xf $(tdir)/$$tarball
 	cd $$pdir
-	./autogen.sh \
-	&& ./configure SHELL=$(ibdir)/bash --prefix=$(idir) \
-	&& make -j$(numthreads) SHELL=$(ibdir)/bash \
-	&& make install \
-	&& cd .. \
-	&& rm -rf $$pdir \
-	&& cd $$topdir \
-	&& echo "Apache log4cxx $(apachelog4cxx-version)" > $@
-
-$(ibidir)/apr: $(tdir)/apr-$(apr-version).tar.gz
-	$(call gbuild, apr-$(apr-version), ,--disable-static) \
-	&& echo "Apache Portable Runtime $(apr-version)" > $@
-
-$(ibidir)/apr-util: $(ibidir)/apr \
-                    $(tdir)/apr-util-$(apr-util-version).tar.gz
+	./autogen.sh
+	./configure SHELL=$(ibdir)/bash --prefix=$(idir)
+	make -j$(numthreads) SHELL=$(ibdir)/bash
+	make install
+	cd ..
+	rm -rf $$pdir
+	cd $$topdir
+	echo "Apache log4cxx $(apachelog4cxx-version)" > $@
+
+$(ibidir)/apr-$(apr-version):
+	tarball=apr-$(apr-version).tar.gz
+	$(call import-source, $(apr-url), $(apr-checksum))
+	$(call gbuild, apr-$(apr-version), ,--disable-static)
+	echo "Apache Portable Runtime $(apr-version)" > $@
+
+$(ibidir)/apr-util-$(apr-util-version): $(ibidir)/apr-$(apr-version)
+	tarball=apr-util-$(apr-util-version).tar.gz
+	$(call import-source, $(apr-util-url), $(apr-util-checksum))
 	$(call gbuild, apr-util-$(apr-util-version), , \
 	               --disable-static \
 	               --with-apr=$(idir) \
 	               --with-openssl=$(idir) \
-	               --with-crypto ) \
-	&& echo "Apache Portable Runtime Utility $(apr-util-version)" > $@
+	               --with-crypto )
+	echo "Apache Portable Runtime Utility $(apr-util-version)" > $@
+
+$(ibidir)/atlas-$(atlas-version):
 
-$(ibidir)/atlas: $(tdir)/atlas-$(atlas-version).tar.bz2 \
-                 $(tdir)/lapack-$(lapack-version).tar.gz
+	tarball=lapack-$(lapack-version).tar.gz
+	$(call import-source, $(lapack-url), $(lapack-checksum))
+
+	tarball=atlas-$(atlas-version).tar.bz2
+	$(call import-source, $(atlas-url), $(atlas-checksum))
 
         # Get the operating system specific features (how to get
         # CPU frequency and the library suffixes). To make the steps
@@ -470,39 +305,46 @@ $(ibidir)/atlas: $(tdir)/atlas-$(atlas-version).tar.bz2 \
         # See if the shared libraries should be build for a single CPU
         # thread or multiple threads.
 	N=$$(nproc)
-	srcdir=$$(pwd)/reproduce/src/make
+	srcdir=$$(pwd)/reproduce/software/make
 	if [ $$N = 1 ]; then
-	  sharedmk=$$srcdir/dependencies-atlas-single.mk
+	  sharedmk=$$srcdir/atlas-single.mk
 	else
-	  sharedmk=$$srcdir/dependencies-atlas-multiple.mk
+	  sharedmk=$$srcdir/atlas-multiple.mk
 	fi
 
         # The linking step here doesn't recognize the `-Wl' in the
         # `rpath_command'.
 	export LDFLAGS=-L$(ildir)
-	cd $(ddir) \
-	&& tar xf $(tdir)/atlas-$(atlas-version).tar.bz2 \
-	&& cd ATLAS \
-	&& rm -rf build \
-	&& mkdir build \
-	&& cd build \
-	&& ../configure -b 64 -D c -DPentiumCPS=$$core \
+	cd $(ddir)
+	tar xf $(tdir)/atlas-$(atlas-version).tar.bz2
+	cd ATLAS
+	rm -rf build
+	mkdir build
+	cd build
+	../configure -b 64 -D c -DPentiumCPS=$$core \
 	             --with-netlib-lapack-tarfile=$(tdir)/lapack-$(lapack-version).tar.gz \
 	             --cripple-atlas-performance \
 	             -Fa alg -fPIC --shared $$clangflag \
-	             --prefix=$(idir) \
-	&& make \
-	&& if [ "x$(on_mac_os)" != xyes ]; then \
-	     cd lib && make -f $$sharedmk && cd .. \
-	     && for l in lib/*.$$s*; do \
-	          patchelf --set-rpath $(ildir) $$l; done \
-	     && cp -d lib/*.$$s* $(ildir) \
-	     && ln -fs $(ildir)/libblas.$$s  $(ildir)/libblas.$$m \
-	     && ln -fs $(ildir)/libf77blas.$$s $(ildir)/libf77blas.$$m \
-	     && ln -fs $(ildir)/liblapack.$$f  $(ildir)/liblapack.$$s \
-	     && ln -fs $(ildir)/liblapack.$$f  $(ildir)/liblapack.$$m; \
-	   fi \
-	&& make install
+	             --prefix=$(idir)
+
+        # Static build.
+	make
+
+        # Currently the shared libraries have problems on macOS.
+	if [ "x$(on_mac_os)" != xyes ]; then
+	     cd lib
+	     make -f $$sharedmk
+	     cd ..
+	     for l in lib/*.$$s*; do patchelf --set-rpath $(ildir) $$l; done
+	     cp -d lib/*.$$s* $(ildir)
+	     ln -fs $(ildir)/libblas.$$s  $(ildir)/libblas.$$m
+	     ln -fs $(ildir)/libf77blas.$$s $(ildir)/libf77blas.$$m
+	     ln -fs $(ildir)/liblapack.$$f  $(ildir)/liblapack.$$s
+	     ln -fs $(ildir)/liblapack.$$f  $(ildir)/liblapack.$$m
+	   fi
+
+        # Install the libraries.
+	make install
 
         # We need to check the existance of `libptlapack.a', but we can't
         # do this in the `&&' steps above (it will conflict). So we'll do
@@ -521,31 +363,37 @@ $(ibidir)/atlas: $(tdir)/atlas-$(atlas-version).tar.bz2 \
 	fi
 
 # Boost doesn't use the standard GNU Build System.
-$(ibidir)/boost: $(ibidir)/openmpi \
-                 $(ibidir)/python \
-                 $(tdir)/boost-$(boost-version).tar.gz
-	vstr=$$(echo $(boost-version) | sed -e's/\./_/g')
-	rm -rf $(ddir)/boost_$$vstr
-	topdir=$(pwd); cd $(ddir);
-	tar xf $(word 1,$(filter $(tdir)/%,$^)) \
-	&& cd boost_$$vstr \
-	&& ./bootstrap.sh --prefix=$(idir) --with-libraries=all \
-	                  --with-python=python3 \
-	&& echo "using mpi ;" > project-config.jam \
-	&& ./b2 stage threading=multi link=shared --prefix=$(idir) -j$(numthreads) \
-	&& ./b2 install threading=multi link=shared --prefix=$(idir) -j$(numthreads) \
-	&& cd $$topdir \
-	&& rm -rf $(ddir)/boost_$$vstr \
-	&& echo "Boost $(boost-version)" > $@
-
-$(ibidir)/cfitsio: $(ibidir)/curl \
-                   $(tdir)/cfitsio-$(cfitsio-version).tar.gz
+$(ibidir)/boost-$(boost-version): \
+                $(ibidir)/python-$(python-version) \
+                $(ibidir)/openmpi-$(openmpi-version)
+	tarball=boost-$(boost-version).tar.lz
+	$(call import-source, $(boost-url), $(boost-checksum))
+	unpackdir=boost-$(boost-version)
+	rm -rf $(ddir)/$$unpackdir
+	topdir=$(pwd)
+	cd $(ddir)
+	tar xf $(tdir)/$$tarball
+	cd $$unpackdir
+	./bootstrap.sh --prefix=$(idir) --with-libraries=all \
+	               --with-python=python3
+	echo "using mpi ;" > project-config.jam
+	./b2 stage threading=multi link=shared --prefix=$(idir) -j$(numthreads)
+	./b2 install threading=multi link=shared --prefix=$(idir) -j$(numthreads)
+	cd $$topdir
+	rm -rf $(ddir)/$$unpackdir
+	echo "Boost $(boost-version)" > $@
+
+$(ibidir)/cfitsio-$(cfitsio-version):
+
+        # Download the tarball
+	tarball=cfitsio-$(cfitsio-version).tar.gz
+	$(call import-source, $(cfitsio-url), $(cfitsio-checksum))
 
         # CFITSIO hard-codes '@rpath' inside the shared library on
         # Mac systems. So we need to change it to our library
         # installation path. It doesn't affect GNU/Linux, so we'll
         # just do it in any case to keep things clean.
-	topdir=$(pwd); cd $(ddir); tar xf $(word 1,$(filter $(tdir)/%,$^))
+	topdir=$(pwd); cd $(ddir); tar xf $(tdir)/$$tarball
 	customtar=cfitsio-$(cfitsio-version)-custom.tar.gz
 	cd cfitsio-$(cfitsio-version)
 	sed configure -e's|@rpath|$(ildir)|g' > configure_tmp
@@ -558,68 +406,82 @@ $(ibidir)/cfitsio: $(ibidir)/curl \
         # Continue the standard build on the customized tarball. Note that
         # with the installation of CFITSIO, `fpack' and `funpack' are not
         # installed by default. Because of that, they are added explicity.
-	export gbuild_tar=$$customtar
+	export gbuild_tar=$(ddir)/$$customtar
 	$(call gbuild, cfitsio-$(cfitsio-version), , \
 	               --enable-sse2 --enable-reentrant \
-	               --with-bzip2=$(idir), , make shared fpack funpack) \
-	&& rm $$customtar \
-	&& echo "CFITSIO $(cfitsio-version)" > $@
-
-$(ibidir)/cairo: $(ibidir)/freetype \
-                 $(ibidir)/libpng \
-                 $(ibidir)/pixman \
-                 $(tdir)/cairo-$(cairo-version).tar.xz
+	               --with-bzip2=$(idir), , make shared fpack funpack)
+	rm $$customtar
+	echo "CFITSIO $(cfitsio-version)" > $@
+
+$(ibidir)/cairo-$(cairo-version): \
+                $(ibidir)/pixman-$(pixman-version) \
+                $(ibidir)/libpng-$(libpng-version) \
+                $(ibidir)/freetype-$(freetype-version)
+	tarball=cairo-$(cairo-version).tar.xz
+	$(call import-source, $(cairo-url), $(cairo-checksum))
 	$(call gbuild, cairo-$(cairo-version), static, \
-	               --with-x=no, -j$(numthreads) V=1) \
-	&& echo "Cairo $(cairo-version)" > $@
+	               --with-x=yes, -j$(numthreads) V=1)
+	echo "Cairo $(cairo-version)" > $@
 
 # Eigen is just headers! So it doesn't need to be compiled. Once unpacked
 # it has a checksum after `eigen-eigen', so we'll just use a `*' to choose
 # the unpacked directory.
-$(ibidir)/eigen: $(tdir)/eigen-$(eigen-version).tar.gz
+$(ibidir)/eigen-$(eigen-version):
+	tarball=eigen-$(eigen-version).tar.gz
+	$(call import-source, $(eigen-url), $(eigen-checksum))
 	rm -rf $(ddir)/eigen-eigen-*
-	topdir=$(pwd); cd $(ddir); tar xf $(word 1,$(filter $(tdir)/%,$^))
+	topdir=$(pwd); cd $(ddir); tar xf $(tdir)/$$tarball
 	cd eigen-eigen-*
-	cp -r Eigen $(iidir)/eigen3 \
-	&& cd $$topdir \
-	&& rm -rf $(ddir)/eigen-eigen-* \
-	&& echo "Eigen $(eigen-version)" > $@
+	cp -r Eigen $(iidir)/eigen3
+	cd $$topdir
+	rm -rf $(ddir)/eigen-eigen-*
+	echo "Eigen $(eigen-version)" > $@
+
+$(ibidir)/expat-$(expat-version):
+	tarball=expat-$(expat-version).tar.lz
+	$(call import-source, $(expat-url), $(expat-checksum))
+	$(call gbuild, expat-$(expat-version), static)
+	echo "Expat $(expat-version)" > $@
 
-$(ibidir)/expat: $(tdir)/expat-$(expat-version).tar.lz
-	$(call gbuild, expat-$(expat-version), static) \
-	&& echo "Expat $(expat-version)" > $@
+$(ibidir)/fftw-$(fftw-version):
+        # Prepare the source tarball.
+	tarball=fftw-$(fftw-version).tar.gz
+	$(call import-source, $(fftw-url), $(fftw-checksum))
 
-$(ibidir)/fftw: $(tdir)/fftw-$(fftw-version).tar.gz
         # FFTW's single and double precission libraries must be built
         # independently: for the the single-precision library, we need to
         # add the `--enable-float' option. We will build this first, then
         # the default double-precision library.
 	confop="--enable-shared --enable-threads --enable-avx --enable-sse2"
 	$(call gbuild, fftw-$(fftw-version), static, \
-	               $$confop --enable-float) \
-	&& $(call gbuild, fftw-$(fftw-version), static, \
-	               $$confop) \
-	&& cp $(dtexdir)/fftw.tex $(ictdir)/ \
-	&& echo "FFTW $(fftw-version) \citep{fftw}" > $@
-
-# Freetype is necessary to install matplotlib
-$(ibidir)/freetype: $(ibidir)/libpng \
-                    $(tdir)/freetype-$(freetype-version).tar.gz
-	$(call gbuild, freetype-$(freetype-version), static) \
-	&& echo "FreeType $(freetype-version)" > $@
-
-$(ibidir)/gsl: $(tdir)/gsl-$(gsl-version).tar.gz
-	$(call gbuild, gsl-$(gsl-version), static) \
-	&& echo "GNU Scientific Library $(gsl-version)" > $@
-
-$(ibidir)/hdf5: $(ibidir)/openmpi \
-                $(tdir)/hdf5-$(hdf5-version).tar.gz
-	export CC=mpicc; \
-	export FC=mpif90; \
+	               $$confop --enable-float)
+	$(call gbuild, fftw-$(fftw-version), static, \
+	               $$confop)
+	cp $(dtexdir)/fftw.tex $(ictdir)/
+	echo "FFTW $(fftw-version) \citep{fftw}" > $@
+
+$(ibidir)/freetype-$(freetype-version): $(ibidir)/libpng-$(libpng-version)
+	tarball=freetype-$(freetype-version).tar.gz
+	$(call import-source, $(freetype-url), $(freetype-checksum))
+	$(call gbuild, freetype-$(freetype-version), static)
+	echo "FreeType $(freetype-version)" > $@
+
+$(ibidir)/gsl-$(gsl-version):
+	tarball=gsl-$(gsl-version).tar.gz
+	$(call import-source, $(gsl-url), $(gsl-checksum))
+	$(call gbuild, gsl-$(gsl-version), static)
+	echo "GNU Scientific Library $(gsl-version)" > $@
+
+$(ibidir)/hdf5-$(hdf5-version): $(ibidir)/openmpi-$(openmpi-version)
+	export CC=mpicc
+	export FC=mpif90
+	tarball=hdf5-$(hdf5-version).tar.gz
+	$(call import-source, $(hdf5-url), $(hdf5-checksum))
 	$(call gbuild, hdf5-$(hdf5-version), static, \
 	               --enable-parallel \
-	               --enable-fortran, -j$(numthreads) V=1) \
-	&& echo "HDF5 library $(hdf5-version)" > $@
+	               --enable-fortran, \
+	               -j$(numthreads) V=1)
+	echo "HDF5 library $(hdf5-version)" > $@
 
 # HEALPix includes the source of its C, C++, Python (and several other
 # languages) libraries within one tarball. We will include the Python
@@ -634,13 +496,15 @@ $(ibidir)/hdf5: $(ibidir)/openmpi \
 ifeq ($(strip $(top-level-python)),)
 healpix-python-dep =
 else
-healpix-python-dep = $(ipydir)/matplotlib $(ipydir)/astropy
+healpix-python-dep = $(ipydir)/matplotlib-$(matplotlib-version) \
+                     $(ipydir)/astropy-$(astropy-version)
 endif
-$(ibidir)/healpix: $(ibidir)/cfitsio \
-                   $(ibidir)/autoconf \
-                   $(ibidir)/automake \
-                   $(healpix-python-dep) \
-                   $(tdir)/healpix-$(healpix-version).tar.gz
+$(ibidir)/healpix-$(healpix-version): $(healpix-python-dep) \
+                  $(ibidir)/cfitsio-$(cfitsio-version) \
+                  $(ibidir)/autoconf-$(autoconf-version) \
+                  $(ibidir)/automake-$(automake-version)
+	tarball=healpix-$(healpix-version).tar.gz
+	$(call import-source, $(healpix-url), $(healpix-checksum))
 	if [ x"$(healpix-python-dep)" = x ]; then
 	   pycommand1="echo no-healpy-because-no-other-python"
 	   pycommand2="echo no-healpy-because-no-other-python"
@@ -650,130 +514,194 @@ $(ibidir)/healpix: $(ibidir)/cfitsio \
 	fi
 	rm -rf $(ddir)/Healpix_$(healpix-version)
 	topdir=$(pwd); cd $(ddir);
-	tar xf $(word 1,$(filter $(tdir)/%,$^))
-	&& cd Healpix_$(healpix-version)/src/C/autotools/ \
-	&& autoreconf --install \
-	&& ./configure --prefix=$(idir) \
-	&& make V=1 -j$(numthreads) SHELL=$(ibdir)/bash \
-	&& make install \
-	&& cd ../../cxx/autotools/ \
-	&& autoreconf --install \
-	&& ./configure --prefix=$(idir) \
-	&& make V=1 -j$(numthreads) SHELL=$(ibdir)/bash \
-	&& make install \
-	&& cd ../../healpy \
-	&& $$pycommand1 \
-	&& $$pycommand2 \
-	&& cd $$topdir \
-	&& rm -rf $(ddir)/Healpix_$(healpix-version) \
-	&& cp $(dtexdir)/healpix.tex $(ictdir)/ \
-	&& echo "HEALPix $(healpix-version) \citep{healpix}" > $@
-
-$(ibidir)/libjpeg: $(tdir)/jpegsrc.$(libjpeg-version).tar.gz
-	$(call gbuild, jpeg-9b, static,,V=1) \
-	&& echo "Libjpeg $(libjpeg-version)" > $@
-
-$(ibidir)/libnsl: $(ibidir)/libtirpc \
-                  $(ibidir)/rpcsvc-proto \
-                  $(tdir)/libnsl-$(libnsl-version).tar.gz
+	tar xf $(tdir)/$$tarball
+	cd Healpix_$(healpix-version)/src/C/autotools/
+	autoreconf --install
+	./configure --prefix=$(idir)
+	make V=1 -j$(numthreads) SHELL=$(ibdir)/bash
+	make install
+	cd ../../cxx/autotools/
+	autoreconf --install
+	./configure --prefix=$(idir)
+	make V=1 -j$(numthreads) SHELL=$(ibdir)/bash
+	make install
+	cd ../../healpy
+	$$pycommand1
+	$$pycommand2
+	cd $$topdir
+	rm -rf $(ddir)/Healpix_$(healpix-version)
+	cp $(dtexdir)/healpix.tex $(ictdir)/
+	echo "HEALPix $(healpix-version) \citep{healpix}" > $@
+
+$(ibidir)/libjpeg-$(libjpeg-version):
+	tarball=jpegsrc.$(libjpeg-version).tar.gz
+	$(call import-source, $(libjpeg-url), $(libjpeg-checksum))
+	$(call gbuild, jpeg-9b, static,,V=1)
+	echo "Libjpeg $(libjpeg-version)" > $@
+
+$(ibidir)/libnsl-$(libnsl-version): \
+                 $(ibidir)/libtirpc-$(libtirpc-version) \
+                 $(ibidir)/rpcsvc-proto-$(rpcsvc-proto-version)
+	tarball=libnsl-$(libnsl-version).tar.gz
+	$(call import-source, $(libnsl-url), $(libnsl-checksum))
 	$(call gbuild, libnsl-$(libnsl-version), static, \
-	               --sysconfdir=$(idir)/etc) \
-	&& echo "Libnsl $(libnsl-version)" > $@
+	               --sysconfdir=$(idir)/etc)
+	echo "Libnsl $(libnsl-version)" > $@
+
+$(ibidir)/libpaper-$(libpaper-version): \
+                   $(ibidir)/automake-$(automake-version)
 
-$(ibidir)/libpng: $(tdir)/libpng-$(libpng-version).tar.xz
-	$(call gbuild, libpng-$(libpng-version), static) \
-	&& echo "Libpng $(libpng-version)" > $@
+        # Download the tarball.
+	tarball=libpaper-$(libpaper-version).tar.gz
+	$(call import-source, $(libpaper-url), $(libpaper-checksum))
 
-$(ibidir)/libtiff: $(ibidir)/libjpeg \
-                   $(tdir)/tiff-$(libtiff-version).tar.gz
+        # Unpack, build the configure system, build and install.
+	cd $(ddir)
+	tar -xf $(tdir)/$$tarball
+	unpackdir=libpaper-$(libpaper-version)
+	cd $$unpackdir
+	autoreconf -fi
+	./configure --prefix=$(idir) --sysconfdir=$(idir)/etc \
+	            --disable-static
+	make
+	make install
+	cd ..
+	rm -rf $$unpackdir
+
+        # Post-processing: according to Linux From Scratch, libpaper
+        # expects that packages will install files into this directory and
+        # 'paperconfig' is a script which will invoke 'run-parts' if
+        # '/etc/libpaper.d' exists
+	mkdir -vp $(idir)/etc/libpaper.d
+	sed -e's|MANEAGESHELL|$(SHELL)|' $(shsrcdir)/run-parts.in \
+	    > $(ibdir)/run-parts
+	chmod +x $(ibdir)/run-parts
+	echo "Libpaper $(libpaper-version)" > $@
+
+$(ibidir)/libpng-$(libpng-version):
+	tarball=libpng-$(libpng-version).tar.xz
+	$(call import-source, $(libpng-url), $(libpng-checksum))
+	$(call gbuild, libpng-$(libpng-version), static)
+	echo "Libpng $(libpng-version)" > $@
+
+$(ibidir)/libtiff-$(libtiff-version): $(ibidir)/libjpeg-$(libjpeg-version)
+	tarball=tiff-$(libtiff-version).tar.gz
+	$(call import-source, $(libtiff-url), $(libtiff-checksum))
 	$(call gbuild, tiff-$(libtiff-version), static, \
 	               --disable-jbig \
 	               --disable-webp \
-	               --disable-zstd) \
-	&& echo "Libtiff $(libtiff-version)" > $@
+	               --disable-zstd)
+	echo "Libtiff $(libtiff-version)" > $@
 
-$(ibidir)/libtirpc: $(tdir)/libtirpc-$(libtirpc-version).tar.bz2
+$(ibidir)/libtirpc-$(libtirpc-version):
+	tarball=libtirpc-$(libtirpc-version).tar.bz2
+	$(call import-source, $(libtirpc-url), $(libtirpc-checksum))
 	$(call gbuild, libtirpc-$(libtirpc-version), static, \
-	               --disable-gssapi, V=1) \
+	               --disable-gssapi, V=1)
 	echo "libtirpc $(libtirpc-version)" > $@
 
-$(ibidir)/openblas: $(tdir)/openblas-$(openblas-version).tar.gz
-	if [ x$(on_mac_os) = xyes ]; then \
-	  export CC=clang; \
-	fi; \
-	cd $(ddir) \
-	&& tar xf $(word 1,$(filter $(tdir)/%,$^)) \
-	&& cd OpenBLAS-$(openblas-version) \
-	&& make \
-	&& make PREFIX=$(idir) install \
-	&& cd .. \
-	&& rm -rf OpenBLAS-$(openblas-version) \
-	&& echo "OpenBLAS $(openblas-version)" > $@
-
-$(ibidir)/openmpi: $(tdir)/openmpi-$(openmpi-version).tar.gz
+$(ibidir)/openblas-$(openblas-version):
+	tarball=OpenBLAS-$(openblas-version).tar.gz
+	$(call import-source, $(openblas-url), $(openblas-checksum))
+	if [ x$(on_mac_os) = xyes ]; then export CC=clang; fi
+	cd $(ddir)
+	tar xf $(tdir)/$$tarball
+	cd OpenBLAS-$(openblas-version)
+	make -j$(numthreads)
+	make PREFIX=$(idir) install
+	cd ..
+	rm -rf OpenBLAS-$(openblas-version)
+	echo "OpenBLAS $(openblas-version)" > $@
+
+$(ibidir)/openmpi-$(openmpi-version):
+	tarball=openmpi-$(openmpi-version).tar.gz
+	$(call import-source, $(openmpi-url), $(openmpi-checksum))
 	$(call gbuild, openmpi-$(openmpi-version), static, , \
-	               -j$(numthreads) V=1) \
-	&& echo "Open MPI $(openmpi-version)" > $@
+	               -j$(numthreads) V=1)
+	echo "Open MPI $(openmpi-version)" > $@
 
 # IMPORTANT NOTE: The build instructions for OpenSSH are defined here, but
 # it is best that it not be prerequisite of any program and thus not built
 # within the project because of all the security issues it may cause. Only
 # enable/build it in a project with caution, and if there is no other
 # solution (for example to disable SSH in a program that may ask for it.
-$(ibidir)/openssh: $(tdir)/openssh-$(openssh-version).tar.gz
+$(ibidir)/openssh-$(openssh-version):
+	tarball=openssh-$(openssh-version).tar.gz
+	$(call import-source, $(openssh-url), $(openssh-checksum))
 	$(call gbuild, openssh-$(openssh-version), static, \
 	               --with-privsep-path=$(ibdir)/.ssh_privsep \
 	               --with-privsep-user=nobody \
 	               --with-md5-passwords \
 	               --with-ssl-engine \
-	               , -j$(numthreads) V=1) \
-	&& echo "OpenSSH $(openssh-version)" > $@
+	               , -j$(numthreads) V=1)
+	echo "OpenSSH $(openssh-version)" > $@
 
-$(ibidir)/pixman: $(tdir)/pixman-$(pixman-version).tar.gz
+$(ibidir)/pixman-$(pixman-version):
+	tarball=pixman-$(pixman-version).tar.gz
+	$(call import-source, $(pixman-url), $(pixman-checksum))
 	$(call gbuild, pixman-$(pixman-version), static, , \
-	                   -j$(numthreads) V=1) \
-	&& echo "Pixman $(pixman-version)" > $@
+	               -j$(numthreads) V=1)
+	echo "Pixman $(pixman-version)" > $@
 
-$(ibidir)/rpcsvc-proto: $(tdir)/rpcsvc-proto-$(rpcsvc-proto-version).tar.xz
-	$(call gbuild, rpcsvc-proto-$(rpcsvc-proto-version), static) \
-	&& echo "rpcsvc $(rpcsvc-proto-version)" > $@
+$(ibidir)/rpcsvc-proto-$(rpcsvc-proto-version):
+        # 'libintl' is installed as part of GNU Gettext in
+        # 'basic.mk'. rpcsvc-proto needs to link with it on macOS.
+	if [ x$(on_mac_os) = xyes ]; then
+	  export CC=clang
+	  export CXX=clang++
+	  export LDFLAGS="-lintl $$LDFLAGS"
+	fi
 
-$(ibidir)/tides: $(tdir)/tides-$(tides-version).tar.gz
+        # Download the tarball and build rpcsvc-proto.
+	tarball=rpcsvc-proto-$(rpcsvc-proto-version).tar.xz
+	$(call import-source, $(rpcsvc-proto-url), $(rpcsvc-proto-checksum))
+	$(call gbuild, rpcsvc-proto-$(rpcsvc-proto-version), static)
+	echo "rpcsvc $(rpcsvc-proto-version)" > $@
+
+$(ibidir)/tides-$(tides-version):
+	tarball=tides-$(tides-version).tar.gz
+	$(call import-source, $(tides-url), $(tides-checksum))
 	$(call gbuild, tides-$(tides-version), static,\
-	               --with-gmp=$(idir) --with-mpfr=$(idir)) \
-	&& cp $(dtexdir)/tides.tex $(ictdir)/ \
-	&& echo "TIDES $(tides-version) \citep{tides}" > $@
-
-$(ibidir)/valgrind: $(ibidir)/patch \
-                    $(ibidir)/autoconf \
-                    $(ibidir)/automake \
-                    $(tdir)/valgrind-$(valgrind-version).tar.bz2
+	               --with-gmp=$(idir) --with-mpfr=$(idir))
+	cp $(dtexdir)/tides.tex $(ictdir)/
+	echo "TIDES $(tides-version) \citep{tides}" > $@
+
+$(ibidir)/valgrind-$(valgrind-version): \
+                   $(ibidir)/patch-$(patch-version) \
+                   $(ibidir)/autoconf-$(autoconf-version) \
+                   $(ibidir)/automake-$(automake-version)
+        # Import the tarball
+	tarball=valgrind-$(valgrind-version).tar.bz2
+	$(call import-source, $(valgrind-url), $(valgrind-checksum))
+
         # For valgrind-3.15.0, see
         # https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=946329 for a
         # report on an MPI-related compile bug and the two patches
         # below. These two patches and `automake` should allow valgrind to
         # compile with gcc-9.2.0.
-	cd $(ddir) \
-	&& tar -x -f $(word 1,$(filter $(tdir)/%,$^)) \
-	&& valgrinddir=valgrind-$(valgrind-version) \
-	&& cd $${valgrinddir} \
-	&& printf "valgrindir=$${valgrinddir} ; pwd = %s .\n" $$($(ibdir)/pwd) \
-	&& if [ "x$(valgrind-version)" = "x3.15.0" ]; then \
-	     patch --verbose -p1 < $(patchdir)/valgrind-3.15.0-mpi-fix1.patch; \
-	     patch --verbose -p1 < $(patchdir)/valgrind-3.15.0-mpi-fix2.patch; \
-	   fi \
-	&& autoreconf \
-	&& ./configure --prefix=$(idir) \
-	&& make -j$(numthreads) \
-	&& if ! make check -j$(numthreads); then \
-	     echo; echo "Valgrind's 'make check' failed!"; echo; \
-	   fi \
-	&& make install \
-	&& echo "Valgrind $(valgrind-version)" > $@
+	cd $(ddir)
+	tar -xf $(tdir)/$$tarball
+	valgrinddir=valgrind-$(valgrind-version)
+	cd $${valgrinddir}
+	printf "valgrindir=$${valgrinddir} ; pwd = %s .\n" $$($(ibdir)/pwd)
+	if [ "x$(valgrind-version)" = "x3.15.0" ]; then
+	  patch --verbose -p1 < $(patchdir)/valgrind-3.15.0-mpi-fix1.patch
+	  patch --verbose -p1 < $(patchdir)/valgrind-3.15.0-mpi-fix2.patch
+	fi
+	autoreconf
+	./configure --prefix=$(idir)
+	make -j$(numthreads)
+	if ! make check -j$(numthreads); then
+	  echo; echo "Valgrind's 'make check' failed!"; echo
+	fi
+	make install
+	echo "Valgrind $(valgrind-version)" > $@
 
-$(ibidir)/yaml: $(tdir)/yaml-$(yaml-version).tar.gz
-	$(call gbuild, yaml-$(yaml-version), static) \
-	&& echo "LibYAML $(yaml-version)" > $@
+$(ibidir)/yaml-$(yaml-version):
+	tarball=yaml-$(yaml-version).tar.gz
+	$(call import-source, $(yaml-url), $(yaml-checksum))
+	$(call gbuild, yaml-$(yaml-version), static)
+	echo "LibYAML $(yaml-version)" > $@
 
 
 
@@ -800,20 +728,23 @@ $(ibidir)/yaml: $(tdir)/yaml-$(yaml-version).tar.gz
 # functions! But apparently `libgit2' has its own implementation of libiconv
 # that it uses if it can't find libiconv on macOS. So, to fix this problem
 # it is necessary to use the option `-DUSE_ICONV=OFF` in the configure step.
-$(ibidir)/libgit2: $(ibidir)/curl \
-                   $(ibidir)/cmake \
-                   $(tdir)/libgit2-$(libgit2-version).tar.gz
+$(ibidir)/libgit2-$(libgit2-version): $(ibidir)/cmake-$(cmake-version)
+	tarball=libgit2-$(libgit2-version).tar.gz
+	$(call import-source, $(libgit2-url), $(libgit2-checksum))
 	$(call cbuild, libgit2-$(libgit2-version), static, \
 	              -DUSE_SSH=OFF -DBUILD_CLAR=OFF \
-	              -DTHREADSAFE=ON -DUSE_ICONV=OFF ) \
-	&& if [ x$(on_mac_os) = xyes ]; then \
-	     install_name_tool -id $(ildir)/libgit2.28.dylib \
-	                           $(ildir)/libgit2.28.dylib; \
-	   fi \
-	&& echo "Libgit2 $(libgit2-version)" > $@
-
-$(ibidir)/wcslib: $(ibidir)/cfitsio \
-                  $(tdir)/wcslib-$(wcslib-version).tar.bz2
+	              -DTHREADSAFE=ON -DUSE_ICONV=OFF )
+	if [ x$(on_mac_os) = xyes ]; then
+	  install_name_tool -id $(ildir)/libgit2.28.dylib \
+	                        $(ildir)/libgit2.28.dylib
+	fi
+	echo "Libgit2 $(libgit2-version)" > $@
+
+$(ibidir)/wcslib-$(wcslib-version): $(ibidir)/cfitsio-$(cfitsio-version)
+        # Import the tarball.
+	tarball=wcslib-$(wcslib-version).tar.bz2
+	$(call import-source, $(wcslib-url), $(wcslib-checksum))
+
         # If Fortran isn't present, don't build WCSLIB with it.
 	if type gfortran &> /dev/null; then fortranopt="";
 	else fortranopt="--disable-fortran"
@@ -824,12 +755,12 @@ $(ibidir)/wcslib: $(ibidir)/cfitsio \
 	               LIBS="-pthread -lcurl -lm" \
                        --with-cfitsiolib=$(ildir) \
                        --with-cfitsioinc=$(idir)/include \
-                       --without-pgplot $$fortranopt) \
-	&& if [ x$(on_mac_os) = xyes ]; then \
-	     install_name_tool -id $(ildir)/libwcs.6.4.dylib \
-	                           $(ildir)/libwcs.6.4.dylib; \
-	   fi \
-	&& echo "WCSLIB $(wcslib-version)" > $@
+                       --without-pgplot $$fortranopt)
+	if [ x$(on_mac_os) = xyes ]; then
+	  install_name_tool -id $(ildir)/libwcs.6.4.dylib \
+	                        $(ildir)/libwcs.6.4.dylib
+	fi
+	echo "WCSLIB $(wcslib-version)" > $@
 
 
 
@@ -846,51 +777,58 @@ $(ibidir)/wcslib: $(ibidir)/cfitsio \
 # Astrometry-net contains a lot of programs. We need to specify the
 # installation directory and the Python executable (by default it will look
 # for /usr/bin/python)
-$(ibidir)/astrometrynet: $(ibidir)/gsl \
-                         $(ibidir)/swig \
-                         $(ipydir)/numpy \
-                         $(ibidir)/cairo \
-                         $(ibidir)/libpng \
-                         $(ibidir)/netpbm \
-                         $(ibidir)/wcslib \
-                         $(ibidir)/cfitsio \
-                         $(ibidir)/libjpeg \
-                         $(tdir)/astrometry.net-$(astrometrynet-version).tar.gz
+$(ibidir)/astrometrynet-$(astrometrynet-version): \
+                        $(ibidir)/gsl-$(gsl-version) \
+                        $(ibidir)/swig-$(swig-version) \
+                        $(ipydir)/numpy-$(numpy-version) \
+                        $(ibidir)/cairo-$(cairo-version) \
+                        $(ibidir)/libpng-$(libpng-version) \
+                        $(ibidir)/netpbm-$(netpbm-version) \
+                        $(ibidir)/wcslib-$(wcslib-version) \
+                        $(ibidir)/cfitsio-$(cfitsio-version) \
+                        $(ibidir)/libjpeg-$(libjpeg-version)
+
+        # Import the tarball
+	tarball=astrometry.net-$(astrometrynet-version).tar.gz
+	$(call import-source, $(astrometrynet-url), $(astrometrynet-checksum))
+
         # We are modifying the Makefile in two steps because on Mac OS
         # system we do not have `/proc/cpuinfo' nor `free'. Since this is
         # only for the `report.txt', this changes do not causes problems in
         # running `astrometrynet'
-	cd $(ddir) \
-	&& rm -rf astrometry.net-$(astrometrynet-version) \
-	&& if ! tar xf $(word 1,$(filter $(tdir)/%,$^)); then \
-	      echo; echo "Tar error"; exit 1; \
-	   fi \
-	&& cd astrometry.net-$(astrometrynet-version) \
-	&& sed -e 's|cat /proc/cpuinfo|echo "Ignoring CPU info"|' \
-	       -e 's|-free|echo "Ignoring RAM info"|' Makefile > Makefile.tmp \
-	&& mv Makefile.tmp Makefile \
-	&& make \
-	&& make py \
-	&& make extra \
-	&& make install INSTALL_DIR=$(idir) PYTHON_SCRIPT="$(ibdir)/python" \
-	&& cd .. \
-	&& rm -rf astrometry.net-$(astrometrynet-version) \
-	&& cp $(dtexdir)/astrometrynet.tex $(ictdir)/ \
-	&& echo "Astrometry.net $(astrometrynet-version) \citep{astrometrynet}" > $@
-
-$(ibidir)/autoconf: $(tdir)/autoconf-$(autoconf-version).tar.lz
-	$(call gbuild, autoconf-$(autoconf-version), static, ,V=1) \
-	&& echo "GNU Autoconf $(autoconf-version)" > $@
-
-$(ibidir)/automake: $(ibidir)/autoconf \
-                    $(tdir)/automake-$(automake-version).tar.gz
-	$(call gbuild, automake-$(automake-version), static, ,V=1) \
-	&& echo "GNU Automake $(automake-version)" > $@
-
-$(ibidir)/bison: $(ibidir)/help2man \
-                 $(tdir)/bison-$(bison-version).tar.xz
-	$(call gbuild, bison-$(bison-version), static, ,V=1) \
-	&& echo "GNU Bison $(bison-version)" > $@
+	cd $(ddir)
+	rm -rf astrometry.net-$(astrometrynet-version)
+	tar xf $(tdir)/$$tarball
+	cd astrometry.net-$(astrometrynet-version)
+	sed -e 's|cat /proc/cpuinfo|echo "Ignoring CPU info"|' \
+	    -e 's|-free|echo "Ignoring RAM info"|' Makefile > Makefile.tmp
+	mv Makefile.tmp Makefile
+	make
+	make py
+	make extra
+	make install INSTALL_DIR=$(idir) PYTHON_SCRIPT="$(ibdir)/python"
+	cd ..
+	rm -rf astrometry.net-$(astrometrynet-version)
+	cp $(dtexdir)/astrometrynet.tex $(ictdir)/
+	echo "Astrometry.net $(astrometrynet-version) \citep{astrometrynet}" > $@
+
+$(ibidir)/autoconf-$(autoconf-version):
+	tarball=autoconf-$(autoconf-version).tar.lz
+	$(call import-source, $(autoconf-url), $(autoconf-checksum))
+	$(call gbuild, autoconf-$(autoconf-version), static, ,V=1)
+	echo "GNU Autoconf $(autoconf-version)" > $@
+
+$(ibidir)/automake-$(automake-version): $(ibidir)/autoconf-$(autoconf-version)
+	tarball=automake-$(automake-version).tar.gz
+	$(call import-source, $(automake-url), $(automake-checksum))
+	$(call gbuild, automake-$(automake-version), static, ,V=1)
+	echo "GNU Automake $(automake-version)" > $@
+
+$(ibidir)/bison-$(bison-version): $(ibidir)/help2man-$(help2man-version)
+	tarball=bison-$(bison-version).tar.xz
+	$(call import-source, $(bison-url), $(bison-checksum))
+	$(call gbuild, bison-$(bison-version), static, ,V=1 -j$(numthreads))
+	echo "GNU Bison $(bison-version)" > $@
 
 # cdsclient is a set of software written in c to interact with astronomical
 # database servers. It is a dependency of `scamp' to be able to download
@@ -899,57 +837,69 @@ $(ibidir)/bison: $(ibidir)/help2man \
 # programs are scripts and we need to touch them before installing.
 # Otherwise this software will be re-built each time the configure step is
 # invoked.
-$(ibidir)/cdsclient: $(tdir)/cdsclient-$(cdsclient-version).tar.gz
-	cd $(ddir) \
-	&& tar xf $(word 1,$(filter $(tdir)/%,$^)) \
-	&& cd cdsclient-$(cdsclient-version) \
-	&& touch * \
-	&& ./configure --prefix=$(idir) \
-	&& make \
-	&& make install \
-	&& cd .. \
-	&& rm -rf cdsclient-$(cdsclient-version) \
-	&& echo "cdsclient $(cdsclient-version)" > $@
+$(ibidir)/cdsclient-$(cdsclient-version):
+	tarball=cdsclient-$(cdsclient-version).tar.gz
+	$(call import-source, $(cdsclient-url), $(cdsclient-checksum))
+	cd $(ddir)
+	tar xf $(tdir)/$$tarball
+	cd cdsclient-$(cdsclient-version)
+	touch *
+	./configure --prefix=$(idir)
+	make
+	make install
+	cd ..
+	rm -rf cdsclient-$(cdsclient-version)
+	echo "cdsclient $(cdsclient-version)" > $@
 
 # CMake can be built with its custom `./bootstrap' script.
-$(ibidir)/cmake: $(ibidir)/curl \
-                 $(tdir)/cmake-$(cmake-version).tar.gz
+$(ibidir)/cmake-$(cmake-version): $(ibidir)/curl-$(curl-version)
+        # Import the tarball
+	tarball=cmake-$(cmake-version).tar.gz
+	$(call import-source, $(cmake-url), $(cmake-checksum))
+
         # After searching in `bootstrap', I couldn't find `LIBS', only
         # `LDFLAGS'. So the extra libraries are being added to `LDFLAGS',
         # not `LIBS'.
         #
         # On Mac systems, the build complains about `clang' specific
         # features, so we can't use our own GCC build here.
-	if [ x$(on_mac_os) = xyes ]; then \
-	  export CC=clang; \
-	  export CXX=clang++; \
-	fi; \
-	cd $(ddir) \
-	&& rm -rf cmake-$(cmake-version) \
-	&& tar xf $(word 1,$(filter $(tdir)/%,$^)) \
-	&& cd cmake-$(cmake-version) \
-	&& ./bootstrap --prefix=$(idir) --system-curl --system-zlib \
-	               --system-bzip2 --system-liblzma --no-qt-gui \
-	               --parallel=$(numthreads) \
-	&& make -j$(numthreads) LIBS="$$LIBS -lssl -lcrypto -lz" VERBOSE=1  \
-	&& make install \
-	&& cd .. \
-	&& rm -rf cmake-$(cmake-version) \
-	&& echo "CMake $(cmake-version)" > $@
-
-$(ibidir)/flex: $(ibidir)/bison \
-                $(tdir)/flex-$(flex-version).tar.gz
-	$(call gbuild, flex-$(flex-version), static, ,V=1) \
-	&& echo "Flex $(flex-version)" > $@
-
-$(ibidir)/gdb: $(ibidir)/python \
-               $(tdir)/gdb-$(gdb-version).tar.gz
-	$(call gbuild, gdb-$(gdb-version),,,V=1) \
-	&& echo "GNU Project Debugger (GDB) $(gdb-version)" > $@
-
-$(ibidir)/ghostscript: $(ibidir)/libpng \
-                       $(ibidir)/libtiff \
-                       $(tdir)/ghostscript-$(ghostscript-version).tar.gz
+	if [ x$(on_mac_os) = xyes ]; then
+	  export CC=clang
+	  export CXX=clang++
+	fi
+	cd $(ddir)
+	rm -rf cmake-$(cmake-version)
+	tar xf $(tdir)/$$tarball
+	cd cmake-$(cmake-version)
+	./bootstrap --prefix=$(idir) --system-curl --system-zlib \
+	            --system-bzip2 --system-liblzma --no-qt-gui \
+	            --parallel=$(numthreads)
+	make -j$(numthreads) LIBS="$$LIBS -lssl -lcrypto -lz" VERBOSE=1
+	make install
+	cd ..
+	rm -rf cmake-$(cmake-version)
+	echo "CMake $(cmake-version)" > $@
+
+$(ibidir)/flex-$(flex-version): $(ibidir)/bison-$(bison-version)
+	tarball=flex-$(flex-version).tar.lz
+	$(call import-source, $(flex-url), $(flex-checksum))
+	$(call gbuild, flex-$(flex-version), static, ,V=1 -j$(numthreads))
+	echo "Flex $(flex-version)" > $@
+
+$(ibidir)/gdb-$(gdb-version): $(ibidir)/python-$(python-version)
+	tarball=gdb-$(gdb-version).tar.gz
+	$(call import-source, $(gdb-url), $(gdb-checksum))
+	$(call gbuild, gdb-$(gdb-version),,,V=1 -j$(numthreads))
+	echo "GNU Project Debugger (GDB) $(gdb-version)" > $@
+
+$(ibidir)/ghostscript-$(ghostscript-version): \
+                      $(ibidir)/libpng-$(libpng-version) \
+                      $(ibidir)/libtiff-$(libtiff-version)
+
+        # Import the tarball.
+	tarball=ghostscript-$(ghostscript-version).tar.gz
+	$(call import-source, $(ghostscript-url), $(ghostscript-checksum))
+
         # First we need to make sure some necessary X11 libraries that we
         # don't yet install in this template are present on the host
         # system, see https://savannah.nongnu.org/task/?15481 .
@@ -986,35 +936,38 @@ $(ibidir)/ghostscript: $(ibidir)/libpng \
 	fi
 
         # If they were present, go onto building Ghostscript.
-	$(call gbuild, ghostscript-$(ghostscript-version)) \
-	&& echo "GPL Ghostscript $(ghostscript-version)" > $@
-
-$(ibidir)/gnuastro: $(ibidir)/gsl \
-                    $(ibidir)/wcslib \
-                    $(ibidir)/libjpeg \
-                    $(ibidir)/libtiff \
-                    $(ibidir)/libgit2 \
-                    $(ibidir)/ghostscript \
-                    $(tdir)/gnuastro-$(gnuastro-version).tar.lz
-ifeq ($(static_build),yes)
-	staticopts="--enable-static=yes --enable-shared=no";
-endif
-	$(call gbuild, gnuastro-$(gnuastro-version), static, \
-	               $$staticopts, -j$(numthreads)) \
-	&& cp $(dtexdir)/gnuastro.tex $(ictdir)/ \
-	&& echo "GNU Astronomy Utilities $(gnuastro-version) \citep{gnuastro}" > $@
-
-$(ibidir)/help2man: $(tdir)/help2man-$(help2man-version).tar.xz
-	$(call gbuild, help2man-$(help2man-version), static, ,V=1) \
-	&& echo "Help2man $(Help2man-version)" > $@
-
-$(ibidir)/imagemagick: $(ibidir)/zlib \
-                       $(ibidir)/libjpeg \
-                       $(ibidir)/libtiff \
-                       $(tdir)/imagemagick-$(imagemagick-version).tar.xz
+	$(call gbuild, ghostscript-$(ghostscript-version),,,V=1 -j$(numthreads))
+	echo "GPL Ghostscript $(ghostscript-version)" > $@
+
+$(ibidir)/gnuastro-$(gnuastro-version): \
+                   $(ibidir)/gsl-$(gsl-version) \
+                   $(ibidir)/wcslib-$(wcslib-version) \
+                   $(ibidir)/libjpeg-$(libjpeg-version) \
+                   $(ibidir)/libtiff-$(libtiff-version) \
+                   $(ibidir)/libgit2-$(libgit2-version) \
+                   $(ibidir)/ghostscript-$(ghostscript-version)
+	tarball=gnuastro-$(gnuastro-version).tar.lz
+	$(call import-source, $(gnuastro-url), $(gnuastro-checksum))
+	$(call gbuild, gnuastro-$(gnuastro-version), static, , \
+	               -j$(numthreads))
+	cp $(dtexdir)/gnuastro.tex $(ictdir)/
+	echo "GNU Astronomy Utilities $(gnuastro-version) \citep{gnuastro}" > $@
+
+$(ibidir)/help2man-$(help2man-version):
+	tarball=help2man-$(help2man-version).tar.xz
+	$(call import-source, $(help2man-url), $(help2man-checksum))
+	$(call gbuild, help2man-$(help2man-version), static, ,V=1)
+	echo "Help2man $(Help2man-version)" > $@
+
+$(ibidir)/imagemagick-$(imagemagick-version): \
+                      $(ibidir)/zlib-$(zlib-version) \
+                      $(ibidir)/libjpeg-$(libjpeg-version) \
+                      $(ibidir)/libtiff-$(libtiff-version)
+	tarball=imagemagick-$(imagemagick-version).tar.xz
+	$(call import-source, $(imagemagick-url), $(imagemagick-checksum))
 	$(call gbuild, ImageMagick-$(imagemagick-version), static, \
-		       --without-x --disable-openmp, V=1 -j$(numthreads)) \
-	&& echo "ImageMagick $(imagemagick-version)" > $@
+		       --without-x --disable-openmp, V=1 -j$(numthreads))
+	echo "ImageMagick $(imagemagick-version)" > $@
 
 # `imfit' doesn't use the traditional `configure' and `make' to install
 # itself.  Instead of that, it uses `scons'. As a consequence, the
@@ -1025,42 +978,51 @@ $(ibidir)/imagemagick: $(ibidir)/zlib \
 # by `$(idir)'. After that, each compiled program (`imfit', `imfit-mcmc'
 # and `makeimage') is copied into the installation directory and an `rpath'
 # is added.
-$(ibidir)/imfit: $(ibidir)/gsl \
-                 $(ibidir)/fftw \
-                 $(ibidir)/scons \
-                 $(ibidir)/cfitsio \
-                 $(tdir)/imfit-$(imfit-version).tar.gz
-	cd $(ddir) \
-	&& unpackdir=imfit-$(imfit-version) \
-	&& rm -rf $$unpackdir \
-	&& if ! tar xf $(word 1,$(filter $(tdir)/%,$^)); then \
-	      echo; echo "Tar error"; exit 1; \
-	   fi \
-	&& cd $$unpackdir \
-	&& sed -i 's|/usr/local|$(idir)|g' SConstruct \
-	&& sed -i 's|/usr/include|$(idir)/include|g' SConstruct \
-	&& sed -i 's|.append(|.insert(0,|g' SConstruct \
-	&& scons --no-openmp  --no-nlopt \
-	         --cc=$(ibdir)/gcc --cpp=$(ibdir)/g++ \
-	         --header-path=$(idir)/include --lib-path=$(idir)/lib imfit \
-	&& cp imfit $(ibdir) \
-	&& scons --no-openmp  --no-nlopt\
-	         --cc=$(ibdir)/gcc --cpp=$(ibdir)/g++ \
-	         --header-path=$(idir)/include --lib-path=$(idir)/lib \
-                 imfit-mcmc \
-	&& cp imfit-mcmc $(ibdir) \
-	&& scons --no-openmp  --no-nlopt\
-	         --cc=$(ibdir)/gcc --cpp=$(ibdir)/g++ \
-	         --header-path=$(idir)/include --lib-path=$(idir)/lib \
-                 makeimage \
-	&& cp makeimage $(ibdir) \
-	&& cp $(dtexdir)/imfit.tex $(ictdir)/ \
-	&& if [ "x$(on_mac_os)" != xyes ]; then \
-	     for p in imfit imfit-mcmc makeimage; do \
-	         patchelf --set-rpath $(ildir) $(ibdir)/$$p; \
-	     done; \
-	   fi \
-	&& echo "Imfit $(imfit-version) \citep{imfit2015}" > $@
+$(ibidir)/imfit-$(imfit-version): \
+                $(ibidir)/gsl-$(gsl-version) \
+                $(ibidir)/fftw-$(fftw-version) \
+                $(ibidir)/scons-$(scons-version) \
+                $(ibidir)/cfitsio-$(cfitsio-version)
+	tarball=imfit-$(imfit-version).tar.gz
+	$(call import-source, $(imfit-url), $(imfit-checksum))
+
+        # If the C library is in a non-standard location.
+	if ! [ x$(SYS_CPATH) = x ]; then
+	  headerpath="--header-path=$(SYS_CPATH)"
+	fi
+
+        # Unpack and build imfit and its accompanying programs.
+	cd $(ddir)
+	unpackdir=imfit-$(imfit-version)
+	rm -rf $$unpackdir
+	tar xf $(tdir)/$$tarball
+	cd $$unpackdir
+	sed -i 's|/usr/local|$(idir)|g' SConstruct
+	sed -i 's|/usr/include|$(idir)/include|g' SConstruct
+	sed -i 's|.append(|.insert(0,|g' SConstruct
+	scons --no-openmp  --no-nlopt \
+	      --cc=$(ibdir)/gcc --cpp=$(ibdir)/g++ \
+	      --header-path=$(idir)/include $$headerpath \
+	      --lib-path=$(idir)/lib imfit
+	cp imfit $(ibdir)
+	scons --no-openmp  --no-nlopt \
+	      --cc=$(ibdir)/gcc --cpp=$(ibdir)/g++ \
+	      --header-path=$(idir)/include $$headerpath \
+	      --lib-path=$(idir)/lib imfit-mcmc
+	cp imfit-mcmc $(ibdir)
+	scons --no-openmp  --no-nlopt \
+	      --cc=$(ibdir)/gcc --cpp=$(ibdir)/g++ \
+	      --header-path=$(idir)/include $$headerpath \
+	      --lib-path=$(idir)/lib makeimage
+	cp makeimage $(ibdir)
+	cp $(dtexdir)/imfit.tex $(ictdir)/
+	if [ -f $(ibdir)/patchelf ]; then
+	  for p in imfit imfit-mcmc makeimage; do
+	      patchelf --set-rpath $(ildir) $(ibdir)/$$p
+	  done
+	fi
+	cp $(dtexdir)/imfit.tex $(ictdir)/
+	echo "Imfit $(imfit-version) \citep{imfit2015}" > $@
 
 # Minizip 1.x is actually distributed within zlib. It doesn't have its own
 # independent tarball. So we need a custom build, which include the GNU
@@ -1071,39 +1033,39 @@ $(ibidir)/imfit: $(ibidir)/gsl \
 #
 # About deleting the final crypt.h file after installation, see
 # https://bugzilla.redhat.com/show_bug.cgi?id=1424609
-$(ibidir)/minizip: $(ibidir)/automake \
-                   $(tdir)/zlib-$(zlib-version).tar.gz
-	cd $(ddir) \
-	&& unpackdir=minizip-$(minizip-version) \
-	&& rm -rf $$unpackdir \
-	&& mkdir $$unpackdir \
-	&& if ! tar xf $(word 1,$(filter $(tdir)/%,$^)) \
-	            -C$$unpackdir --strip-components=1; then \
-	      echo; echo "Tar error"; exit 1; \
-	   fi \
-	&& cd $$unpackdir\
-	&& ./configure --prefix=$(idir) \
-	&& make \
-	&& cd contrib/minizip \
-	&& cp Makefile Makefile.orig \
-	&& cp ../README.contrib readme.txt \
-	&& autoreconf --install \
-	&& ./configure --prefix=$(idir) \
-	&& make \
-	&& cd ../../ \
-	&& make test \
-	&& cd contrib/minizip \
-	&& make -f Makefile.orig test \
-	&& make install \
-	&& rm $(iidir)/minizip/crypt.h \
-	&& cd ../../.. \
-	&& rm -rf $$unpackdir \
-	&& echo "Minizip $(minizip-version)" > $@
-
-$(ibidir)/missfits: $(tdir)/missfits-$(missfits-version).tar.gz
-	$(call gbuild, missfits-$(missfits-version), static) \
-	&& cp $(dtexdir)/missfits.tex $(ictdir)/ \
-	&& echo "MissFITS $(missfits-version) \citep{missfits}" > $@
+$(ibidir)/minizip-$(minizip-version): $(ibidir)/automake-$(automake-version)
+	tarball=zlib-$(zlib-version).tar.gz
+	$(call import-source, $(minizip-url), $(minizip-checksum))
+	cd $(ddir)
+	unpackdir=minizip-$(minizip-version)
+	rm -rf $$unpackdir
+	mkdir $$unpackdir
+	tar xf $(tdir)/$$tarball -C$$unpackdir --strip-components=1
+	cd $$unpackdir
+	./configure --prefix=$(idir)
+	make
+	cd contrib/minizip
+	cp Makefile Makefile.orig
+	cp ../README.contrib readme.txt
+	autoreconf --install
+	./configure --prefix=$(idir)
+	make
+	cd ../../
+	make test
+	cd contrib/minizip
+	make -f Makefile.orig test
+	make install
+	rm $(iidir)/minizip/crypt.h
+	cd ../../..
+	rm -rf $$unpackdir
+	echo "Minizip $(minizip-version)" > $@
+
+$(ibidir)/missfits-$(missfits-version):
+	tarball=missfits-$(missfits-version).tar.gz
+	$(call import-source, $(missfits-url), $(missfits-checksum))
+	$(call gbuild, missfits-$(missfits-version), static)
+	cp $(dtexdir)/missfits.tex $(ictdir)/
+	echo "MissFITS $(missfits-version) \citep{missfits}" > $@
 
 # Netpbm is a prerequisite of Astrometry-net, it contains a lot of programs.
 # This program has a crazy dialogue installation which is override using the
@@ -1111,58 +1073,78 @@ $(ibidir)/missfits: $(tdir)/missfits-$(missfits-version).tar.gz
 # ask to the user. We give all answers with a pipe to the scripts (configure
 # and install). The questions are different depending on the system (tested
 # on GNU/Linux and Mac OS).
-$(ibidir)/netpbm: $(ibidir)/unzip \
-                  $(ibidir)/libpng \
-                  $(ibidir)/libjpeg \
-                  $(ibidir)/libtiff \
-                  $(ibidir)/libxml2 \
-                  $(tdir)/netpbm-$(netpbm-version).tar.gz
-	if [ x$(on_mac_os) = xyes ]; then \
-	  answers='\n\n$(ildir)\n\n\n\n\n\n$(ildir)/include\n\n$(ildir)/include\n\n$(ildir)/include\nnone\n\n'; \
-	else \
-	  answers='\n\n\n\n\n\n\n\n\n\n\n\n\nnone\n\n\n'; \
-	fi; \
-	cd $(ddir) \
-	&& unpackdir=netpbm-$(netpbm-version) \
-	&& rm -rf $$unpackdir \
-	&& if ! tar xf $(word 1,$(filter $(tdir)/%,$^)); then \
-	      echo; echo "Tar error"; exit 1; \
-	   fi \
-	&& cd $$unpackdir \
-	&& printf "$$answers" | ./configure \
-	&& make \
-	&& rm -rf $(ddir)/$$unpackdir/install \
-	&& make package pkgdir=$(ddir)/$$unpackdir/install \
-	&& printf "$(ddir)/$$unpackdir/install\n$(idir)\n\n\nN\n\n\n\n\nN\n\n" \
-	          | ./installnetpbm \
-	&& cd .. \
-	&& rm -rf $$unpackdir \
-	&& echo "Netpbm $(netpbm-version)" > $@
-
-$(ibidir)/patch: $(tdir)/patch-$(patch-version).tar.gz
-	$(call gbuild, patch-$(patch-version), static, ,V=1) \
-	&& echo "GNU Patch $(patch-version)" > $@
-
-# R programming language
-$(ibidir)/R: $(ibidir)/libpng \
-             $(ibidir)/libjpeg \
-             $(ibidir)/libtiff \
-             $(tdir)/R-$(R-version).tar.gz
-	export R_SHELL=$(SHELL); \
+$(ibidir)/netpbm-$(netpbm-version): \
+                 $(ibidir)/libpng-$(libpng-version) \
+                 $(ibidir)/libjpeg-$(libjpeg-version) \
+                 $(ibidir)/libtiff-$(libtiff-version) \
+                 $(ibidir)/libxml2-$(libxml2-version)
+	tarball=netpbm-$(netpbm-version).tar.gz
+	$(call import-source, $(netpbm-url), $(netpbm-checksum))
+	if [ x$(on_mac_os) = xyes ]; then
+	  answers='\n\n$(ildir)\n\n\n\n\n\n$(ildir)/include\n\n$(ildir)/include\n\n$(ildir)/include\nnone\n\n'
+	else
+	  answers='\n\n\n\n\n\n\n\n\n\n\n\n\nnone\n\n\n'
+	fi
+	cd $(ddir)
+	unpackdir=netpbm-$(netpbm-version)
+	rm -rf $$unpackdir
+	tar xf $(tdir)/$$tarball
+	cd $$unpackdir
+	printf "$$answers" | ./configure
+	make
+	rm -rf $(ddir)/$$unpackdir/install
+	make package pkgdir=$(ddir)/$$unpackdir/install
+	printf "$(ddir)/$$unpackdir/install\n$(idir)\n\n\nN\n\n\n\n\nN\n\n" \
+	       | ./installnetpbm
+	cd ..
+	rm -rf $$unpackdir
+	echo "Netpbm $(netpbm-version)" > $@
+
+$(ibidir)/patch-$(patch-version):
+	tarball=patch-$(patch-version).tar.gz
+	$(call import-source, $(patch-url), $(patch-checksum))
+	$(call gbuild, patch-$(patch-version), static, ,V=1)
+	echo "GNU Patch $(patch-version)" > $@
+
+$(ibidir)/pcre-$(pcre-version):
+	tarball=pcre-$(pcre-version).tar.gz
+	$(call import-source, $(pcre-url), $(pcre-checksum))
+	$(call gbuild, pcre-$(pcre-version), static, \
+	               --enable-pcretest-libreadline \
+	               --enable-unicode-properties \
+	               --includedir=$(iidir)/pcre \
+	               --enable-pcregrep-libbz2 \
+	               --enable-pcregrep-libz \
+	               , V=1 -j$(numthreads))
+	echo "Perl Compatible Regular Expressions $(pcre-version)" > $@
+
+$(ibidir)/R-$(R-version): \
+            $(ibidir)/pcre-$(pcre-version) \
+            $(ibidir)/cairo-$(cairo-version) \
+            $(ibidir)/libpng-$(libpng-version) \
+            $(ibidir)/libjpeg-$(libjpeg-version) \
+            $(ibidir)/libtiff-$(libtiff-version) \
+            $(ibidir)/libpaper-$(libpaper-version)
+	tarball=R-$(R-version).tar.gz
+	$(call import-source, $(R-url), $(R-checksum))
+
+	export R_SHELL=$(SHELL)
 	$(call gbuild, R-$(R-version), static, \
                        --without-x --with-readline \
-	               --disable-openmp) \
-	&& echo "R $(R-version)" > $@
+	               --disable-openmp, -j$(numthreads))
+	echo "R $(R-version)" > $@
 
 # SCAMP documentation says ATLAS is a mandatory prerequisite for using
 # SCAMP. We have ATLAS into the project but there are some problems with the
 # libraries that are not yet solved. However, we tried to install it with
 # the option --enable-openblas and it worked (same issue happened with
 # `sextractor'.
-$(ibidir)/scamp: $(ibidir)/fftw \
-                 $(ibidir)/openblas \
-                 $(ibidir)/cdsclient \
-                 $(tdir)/scamp-$(scamp-version).tar.lz
+$(ibidir)/scamp-$(scamp-version): \
+                $(ibidir)/fftw-$(fftw-version) \
+                $(ibidir)/openblas-$(openblas-version) \
+                $(ibidir)/cdsclient-$(cdsclient-version)
+	tarball=scamp-$(scamp-version).tar.lz
+	$(call import-source, $(scamp-url), $(scamp-checksum))
 	$(call gbuild, scamp-$(scamp-version), static, \
                    --enable-threads \
                    --enable-openblas \
@@ -1170,84 +1152,90 @@ $(ibidir)/scamp: $(ibidir)/fftw \
                    --with-fftw-libdir=$(idir) \
                    --with-fftw-incdir=$(idir)/include \
                    --with-openblas-libdir=$(ildir) \
-                   --with-openblas-incdir=$(idir)/include) \
-	&& cp $(dtexdir)/scamp.tex $(ictdir)/ \
-	&& echo "SCAMP $(scamp-version) \citep{scamp}" > $@
+                   --with-openblas-incdir=$(idir)/include)
+	cp $(dtexdir)/scamp.tex $(ictdir)/
+	echo "SCAMP $(scamp-version) \citep{scamp}" > $@
 
 # Since `scons' doesn't use the traditional GNU installation with
 # `configure' and `make' it is installed manually using `python'.
-$(ibidir)/scons: $(ibidir)/python \
-                 $(tdir)/scons-$(scons-version).tar.gz
-	cd $(ddir) \
-	&& unpackdir=scons-$(scons-version) \
-	&& rm -rf $$unpackdir \
-	&& if ! tar xf $(word 1,$(filter $(tdir)/%,$^)); then \
-	      echo; echo "Tar error"; exit 1; \
-	   fi \
-	&& cd $$unpackdir \
-	&& python setup.py install \
-	&& echo "SCons $(scons-version)" > $@
+$(ibidir)/scons-$(scons-version): $(ibidir)/python-$(python-version)
+	tarball=scons-$(scons-version).tar.gz
+	$(call import-source, $(scons-url), $(scons-checksum))
+	cd $(ddir)
+	unpackdir=scons-$(scons-version)
+	rm -rf $$unpackdir
+	tar xf $(tdir)/$$tarball
+	cd $$unpackdir
+	python setup.py install
+	echo "SCons $(scons-version)" > $@
 
 # Sextractor crashes complaining about not linking with some ATLAS
 # libraries. But we can override this issue since we have Openblas
 # installed, it is just necessary to explicity tell sextractor to use it in
 # the configuration step.
-$(ibidir)/sextractor: $(ibidir)/fftw \
-                      $(ibidir)/openblas \
-                      $(tdir)/sextractor-$(sextractor-version).tar.lz
+$(ibidir)/sextractor-$(sextractor-version): \
+                     $(ibidir)/fftw-$(fftw-version) \
+                     $(ibidir)/openblas-$(openblas-version)
+	tarball=sextractor-$(sextractor-version).tar.lz
+	$(call import-source, $(sextractor-url), $(sextractor-checksum))
 	$(call gbuild, sextractor-$(sextractor-version), static, \
 	               --enable-threads --enable-openblas \
 	               --with-openblas-libdir=$(ildir) \
-	               --with-openblas-incdir=$(idir)/include) \
-	&& ln -fs $(ibdir)/sex $(ibdir)/sextractor \
-	&& cp $(dtexdir)/sextractor.tex $(ictdir)/ \
-	&& echo "SExtractor $(sextractor-version) \citep{sextractor}" > $@
-
-$(ibidir)/swarp: $(ibidir)/fftw \
-                 $(tdir)/swarp-$(swarp-version).tar.gz
+	               --with-openblas-incdir=$(idir)/include)
+	ln -fs $(ibdir)/sex $(ibdir)/sextractor
+	cp $(dtexdir)/sextractor.tex $(ictdir)/
+	echo "SExtractor $(sextractor-version) \citep{sextractor}" > $@
+
+$(ibidir)/swarp-$(swarp-version): $(ibidir)/fftw-$(fftw-version)
+	tarball=swarp-$(swarp-version).tar.gz
+	$(call import-source, $(swarp-url), $(swarp-checksum))
 	$(call gbuild, swarp-$(swarp-version), static, \
-                       --enable-threads) \
-	&& cp $(dtexdir)/swarp.tex $(ictdir)/ \
-	&& echo "SWarp $(swarp-version) \citep{swarp}" > $@
+                       --enable-threads)
+	cp $(dtexdir)/swarp.tex $(ictdir)/
+	echo "SWarp $(swarp-version) \citep{swarp}" > $@
 
-$(ibidir)/swig: $(tdir)/swig-$(swig-version).tar.gz
+$(ibidir)/swig-$(swig-version):
         # Option --without-pcre was a suggestion once the configure step
         # was tried and it failed. It was not recommended but it works!
         # pcr is a dependency of swig
-	$(call gbuild, swig-$(swig-version), static, --without-pcre) \
-	&& echo "Swig $(swig-version)" > $@
-
-$(ibidir)/xlsxio: $(ibidir)/cmake \
-                  $(ibidir)/expat \
-                  $(ibidir)/minizip \
-                  $(tdir)/xlsxio-$(xlsxio-version).tar.gz
-	if [ x$(on_mac_os) = xyes ]; then \
-	  export CC=clang; \
-	  export CXX=clang++; \
-	  export LDFLAGS="$$LDFLAGS -lbz2"; \
-	else \
-	  export LDFLAGS="$$LDFLAGS -lbz2 -lbsd"; \
-	fi; \
+	tarball=swig-$(swig-version).tar.gz
+	$(call import-source, $(swig-url), $(swig-checksum))
+	$(call gbuild, swig-$(swig-version), static, --without-pcre)
+	echo "Swig $(swig-version)" > $@
+
+$(ibidir)/xlsxio-$(xlsxio-version): \
+                 $(ibidir)/cmake-$(cmake-version) \
+                 $(ibidir)/expat-$(expat-version) \
+                 $(ibidir)/minizip-$(minizip-version)
+	tarball=xlsxio-$(xlsxio-version).tar.gz
+	$(call import-source, $(xlsxio-url), $(xlsxio-checksum))
+	if [ x$(on_mac_os) = xyes ]; then
+	  export CC=clang
+	  export CXX=clang++
+	  export LDFLAGS="$$LDFLAGS -lbz2"
+	else
+	  export LDFLAGS="$$LDFLAGS -lbz2 -lbsd"
+	fi
 	$(call cbuild, xlsxio-$(xlsxio-version), static, \
 	       -DMINIZIP_DIR:PATH=$(idir) \
 	       -DMINIZIP_LIBRARIES=$(idir) \
-	       -DMINIZIP_INCLUDE_DIRS=$(iidir)) \
-	&& echo "Correcting internal linking of XLSX I/O executables..." \
-	&& if [ "x$(on_mac_os)" = xyes ]; then \
-	     for f in $(ibdir)/xlsxio_* $(ildir)/libxlsxio_*.dylib; do \
-	       install_name_tool -change  libxlsxio_read.dylib \
-	                         $(ildir)/libxlsxio_read.dylib $$f; \
-	       install_name_tool -change  libxlsxio_write.dylib \
-	                         $(ildir)/libxlsxio_write.dylib $$f; \
-	     done; \
-	   else \
-	     for f in $(ibdir)/xlsxio_* $(ildir)/libxlsxio_*.so; do \
-	       patchelf --set-rpath $(ildir) $$f; \
-	     done; \
-	   fi \
-	&& echo "Deleting XLSX I/O example files..." \
-	&& rm $(ibdir)/example_xlsxio_* \
-	&& echo "XLSX I/O $(xlsxio-version)" > $@
+	       -DMINIZIP_INCLUDE_DIRS=$(iidir))
+	echo "Correcting internal linking of XLSX I/O executables..."
+	if [ "x$(on_mac_os)" = xyes ]; then
+	  for f in $(ibdir)/xlsxio_* $(ildir)/libxlsxio_*.dylib; do
+	    install_name_tool -change  libxlsxio_read.dylib \
+	                      $(ildir)/libxlsxio_read.dylib $$f
+	    install_name_tool -change  libxlsxio_write.dylib \
+	                      $(ildir)/libxlsxio_write.dylib $$f
+	  done
+	else
+	  for f in $(ibdir)/xlsxio_* $(ildir)/libxlsxio_*.so; do
+	     patchelf --set-rpath $(ildir) $$f
+	  done
+	fi
+	echo "Deleting XLSX I/O example files..."
+	rm $(ibdir)/example_xlsxio_*
+	echo "XLSX I/O $(xlsxio-version)" > $@
 
 
 
@@ -1272,11 +1260,11 @@ $(ibidir)/xlsxio: $(ibidir)/cmake \
 # (`ftp.dante.de'), however, it is far too slow (when I tested it). The
 # `rit.edu' server seems to be a good alternative (given the importance of
 # NY on the internet infrastructure).
-tlmirror=http://mirrors.rit.edu/CTAN/systems/texlive/tlnet
+texlive-url=http://mirrors.rit.edu/CTAN/systems/texlive/tlnet
+$(itidir)/texlive-ready-tlmgr: reproduce/software/config/texlive.conf
 
-# The core TeX Live system.
-$(itidir)/texlive-ready-tlmgr: reproduce/software/config/texlive.conf \
-                               $(tdir)/install-tl-unx.tar.gz
+	tarball=install-tl-unx.tar.gz
+	$(call import-source, $(texlive-url), NO-CHECK-SUM)
 
         # Unpack, enter the directory, and install based on the given
         # configuration (prerequisite of this rule).
@@ -1318,7 +1306,7 @@ $(itidir)/texlive-ready-tlmgr: reproduce/software/config/texlive.conf \
         # TeXLive using that. The old tarball will be preserved, but will
         # have an '-OLD' suffix after it.
 	if ./install-tl --profile=texlive.conf -repository \
-	                $(tlmirror) 2> log.txt; then
+	                $(texlive-url) 2> log.txt; then
 
           # Put a symbolic link of the TeX Live executables in `ibdir' to
           # avoid all the complexities of its sub-directories and additions
@@ -1368,7 +1356,7 @@ $(itidir)/texlive-ready-tlmgr: reproduce/software/config/texlive.conf \
 	          $$topdir/reproduce/software/config/texlive.conf \
 	          > texlive.conf
 	      if ./install-tl --profile=texlive.conf -repository \
-	                      $(tlmirror); then
+	                      $(texlive-url); then
 	        ln -fs $(idir)/texlive/maneage/bin/*/* $(ibdir)/
 	        echo "TeX Live is ready." > $@
 	      else
@@ -1398,15 +1386,8 @@ $(itidir)/texlive-ready-tlmgr: reproduce/software/config/texlive.conf \
 # don't currently build biber from source. So we can't choose the library
 # version. But we have the source and build instructions for the `nsl'
 # library. When we later build biber from source, we can easily use them.
-#
-#ifeq ($(on_mac_os),yes)
-#forbiber =
-#else
-#forbiber = $(ibidir)/libnsl
-#endif
 $(itidir)/texlive: reproduce/software/config/texlive-packages.conf \
-                   $(itidir)/texlive-ready-tlmgr \
-                   $(forbiber)
+                   $(itidir)/texlive-ready-tlmgr
 
         # To work with TeX live installation, we'll need the internet.
 	@res=$$(cat $(itidir)/texlive-ready-tlmgr)
@@ -1419,7 +1400,7 @@ $(itidir)/texlive: reproduce/software/config/texlive-packages.conf \
 
           # Before checking LaTeX packages, update tlmgr itself.
 	  tlmgr option backupdir $$backupdir
-	  tlmgr -repository $(tlmirror) update --self
+	  tlmgr -repository $(texlive-url) update --self
 
           # Install all the extra necessary packages. If LaTeX complains
           # about not finding a command/file/what-ever/XXXXXX, simply run
diff --git a/reproduce/software/make/python.mk b/reproduce/software/make/python.mk
index eef8279..ccfbc72 100644
--- a/reproduce/software/make/python.mk
+++ b/reproduce/software/make/python.mk
@@ -3,8 +3,12 @@
 # ------------------------------------------------------------------------
 #                      !!!!! IMPORTANT NOTES !!!!!
 #
-# This Makefile will be run by the initial `./project configure' script. It
-# is not included into the reproduction pipe after that.
+# This Makefile will be loaded into 'high-level.mk', which is called by the
+# `./project configure' script. It is not included into the project
+# afterwards.
+#
+# This Makefile contains instructions to build all the Python-related
+# software within the project.
 #
 # ------------------------------------------------------------------------
 #
@@ -52,274 +56,52 @@ python-major-version = $(shell echo $(python-version) | awk 'BEGIN{FS="."} \
 
 
 
-# Tarballs
-# --------
-#
-# All the necessary tarballs are defined and prepared with this rule.
-#
-# Note that we want the tarballs to follow the convention of NAME-VERSION
-# before the `tar.XX' prefix. For those programs that don't follow this
-# convention, but include the name/version in their tarball names with
-# another format, we'll do the modification before the download so the
-# downloaded file has our desired format.
-pytarballs = $(foreach t, asn1crypto-$(asn1crypto-version).tar.gz \
-                        asteval-$(asteval-version).tar.gz \
-                        astroquery-$(astroquery-version).tar.gz \
-                        astropy-$(astropy-version).tar.gz \
-                        beautifulsoup4-$(beautifulsoup4-version).tar.gz \
-                        certifi-$(certifi-version).tar.gz \
-                        cffi-$(cffi-version).tar.gz \
-                        chardet-$(chardet-version).tar.gz \
-                        corner-$(corner-version).tar.gz \
-                        cryptography-$(cryptography-version).tar.gz \
-                        cycler-$(cycler-version).tar.gz \
-                        cython-$(cython-version).tar.gz \
-                        eigency-$(eigency-version).tar.gz \
-                        emcee-$(emcee-version).tar.gz \
-                        esutil-$(esutil-version).tar.gz \
-                        entrypoints-$(entrypoints-version).tar.gz \
-                        flake8-$(flake8-version).tar.gz \
-                        future-$(future-version).tar.gz \
-                        galsim-$(galsim-version).tar.gz \
-                        h5py-$(h5py-version).tar.gz \
-                        html5lib-$(html5lib-version).tar.gz \
-                        idna-$(idna-version).tar.gz \
-                        jeepney-$(jeepney-version).tar.gz \
-                        kiwisolver-$(kiwisolver-version).tar.gz \
-                        keyring-$(keyring-version).tar.gz \
-                        libffi-$(libffi-version).tar.gz \
-                        lmfit-$(lmfit-version).tar.gz \
-                        lsstdesccoord-$(lsstdesccoord-version).tar.gz \
-                        matplotlib-$(matplotlib-version).tar.gz \
-                        mpi4py-$(mpi4py-version).tar.gz \
-                        mpmath-$(mpmath-version).tar.gz \
-                        numpy-$(numpy-version).zip \
-                        pkgconfig-$(pypkgconfig-version).tar.gz \
-                        pip-$(pip-version).tar.gz \
-                        pexpect-$(pexpect-version).tar.gz \
-                        pybind11-$(pybind11-version).tar.gz \
-                        pycodestyle-$(pycodestyle-version).tar.gz \
-                        pycparser-$(pycparser-version).tar.gz \
-                        pyflakes-$(pyflakes-version).tar.gz \
-                        python-$(python-version).tar.gz \
-                        python-dateutil-$(python-dateutil-version).tar.gz \
-                        pyparsing-$(pyparsing-version).tar.gz \
-                        pyyaml-$(pyyaml-version).tar.gz \
-                        requests-$(requests-version).tar.gz \
-                        scipy-$(scipy-version).tar.gz \
-                        secretstorage-$(secretstorage-version).tar.gz \
-                        setuptools-$(setuptools-version).zip \
-                        setuptools_scm-$(setuptools_scm-version).tar.gz \
-                        sip_tpv-$(sip_tpv-version).tar.gz \
-                        six-$(six-version).tar.gz \
-                        soupsieve-$(soupsieve-version).tar.gz \
-                        sympy-$(sympy-version).tar.gz \
-                        uncertainties-$(uncertainties-version).tar.gz \
-                        urllib3-$(urllib3-version).tar.gz \
-                        webencodings-$(webencodings-version).tar.gz \
-                        virtualenv-$(virtualenv-version).tar.gz \
-                      , $(tdir)/$(t) )
-pytopurl=https://files.pythonhosted.org/packages
-$(pytarballs): $(tdir)/%:
-
-        # Convenience variable
-        # --------------------
-        #
-        # `n' is just for convenience and to avoid having to repeat the
-        # package tarball name in the conditional to find its URL.
-        #
-        # For some packages (for example `python-dateutil', or those with
-        # a number or dash in their name), we need special consideration
-        # because the tokenization above will produce `python' as the
-        # first string.
-	@if [ $* = python-dateutil-$(python-dateutil-version).tar.gz ]; then
-	  n=dateutil
-
-        # elif [ $* = strange-tarball5name-version.tar.gz ]; then
-        #  n=strange5-name
-	else
-          # Remove the version numbers and suffix from the tarball name so
-          # we can search more easily only with the program name. This
-          # requires the first character of the version to be a digit:
-          # packages such as `foo' and `foo-3' will not be distinguished,
-          # but `foo' and `foo2' will be distinguished.
-	  n=$$(echo $* | sed -e's/-[0-9]/ /' -e's/\./ /g' \
-	               | awk '{print $$1}' )
-
-	fi
-
-        # Set the top download link of the requested tarball. The ones
-        # that have non-standard filenames (differing from our archived
-        # tarball names) are treated first, then the standard ones.
-	mergenames=1
-	if [ $$n = cython ]; then
-	  mergenames=0
-	  c=$(cython-checksum)
-	  hash=36/da/fcb979fc8cb486a67a013d6aefefbb95a3e19e67e49dff8a35e014046c5e
-	  h=$(pytopurl)/$$hash/Cython-$(cython-version).tar.gz
-	elif [ $$n = galsim ]; then
-	  mergenames=0
-	  c=$(galsim-checksum)
-	  hash=8f/3b/bbc7cff7590d3624d528564f08745f071e316c67fce154ad38210833c103
-	  h=$(pytopurl)/$$hash/GalSim-$(galsim-version).tar.gz
-	elif [ $$n = lsstdesccoord ]; then
-	  mergenames=0
-	  c=$(lsstdesccoord-checksum)
-	  hash=9d/39/ad17697571c9aed36d20ed9ae0a135e3a734fb7f15a8605f92bf27c3b02c
-	  h=$(pytopurl)/$$hash/LSSTDESC.Coord-$(lsstdesccoord-version).tar.gz
-	elif [ $$n = python ]; then
-	  mergenames=0
-	  c=$(python-checksum)
-	  h=https://www.python.org/ftp/python/$(python-version)/Python-$(python-version).tgz
-	elif [ $$n = pyyaml ]; then
-	  mergenames=0
-	  c=$(pyyaml-checksum)
-	  hash=9f/2c/9417b5c774792634834e730932745bc09a7d36754ca00acf1ccd1ac2594d
-	  h=$(pytopurl)/$$hash/PyYAML-$(pyyaml-version).tar.gz
-	elif [ $$n = libffi ]; then
-	  mergenames=0
-	  c=$(libffi-checksum)
-	  h=ftp://sourceware.org/pub/libffi/libffi-$(libffi-version).tar.gz
-	elif [ $$n = secretstorage  ]; then
-	  mergenames=0
-	  c=$(secretstorage-checksum)
-	  hash=a6/89/df343dbc2957a317127e7ff2983230dc5336273be34f2e1911519d85aeb5
-	  h=$(pytopurl)/$$hash/SecretStorage-$(secretstorage-version).tar.gz
-	elif [ $$n = asn1crypto     ]; then h=fc/f1/8db7daa71f414ddabfa056c4ef792e1461ff655c2ae2928a2b675bfed6b4; c=$(asn1crypto-checksum)
-	elif [ $$n = asteval        ]; then h=50/3f/29b7935c6dc09ee96dc347edc66c57e8ef68d595dd35b763a36a117acc8c; c=$(asteval-checksum)
-	elif [ $$n = astroquery     ]; then h=e2/af/a3cd3b30745832a0e81f5f13327234099aaf5d03b7979ac947a888e68e91; c=$(astroquery-checksum)
-	elif [ $$n = astropy        ]; then h=de/96/7feaca4b9be134128838395a9d924ea0b389ed4381702dcd9d11ae31789f; c=$(astropy-checksum)
-	elif [ $$n = beautifulsoup4 ]; then h=80/f2/f6aca7f1b209bb9a7ef069d68813b091c8c3620642b568dac4eb0e507748; c=$(beautifulsoup4-checksum)
-	elif [ $$n = certifi        ]; then h=55/54/3ce77783acba5979ce16674fc98b1920d00b01d337cfaaf5db22543505ed; c=$(certifi-checksum)
-	elif [ $$n = cffi           ]; then h=64/7c/27367b38e6cc3e1f49f193deb761fe75cda9f95da37b67b422e62281fcac; c=$(cffi-checksum)
-	elif [ $$n = chardet        ]; then h=fc/bb/a5768c230f9ddb03acc9ef3f0d4a3cf93462473795d18e9535498c8f929d; c=$(chardet-checksum)
-	elif [ $$n = corner         ]; then h=65/af/a7ba022f2d5787f51db91b5550cbe8e8c40a6eebd8f15119e743a09a9c19; c=$(corner-checksum)
-	elif [ $$n = cryptography   ]; then h=07/ca/bc827c5e55918ad223d59d299fff92f3563476c3b00d0a9157d9c0217449; c=$(cryptography-checksum)
-	elif [ $$n = cycler         ]; then h=c2/4b/137dea450d6e1e3d474e1d873cd1d4f7d3beed7e0dc973b06e8e10d32488; c=$(cycler-checksum)
-	elif [ $$n = eigency        ]; then h=fb/6e/bc4359fbfb0bb0b588ec328251b0d0836bdd7c0a4c568959ea06df023e18; c=$(eigency-checksum)
-	elif [ $$n = emcee          ]; then h=f0/c0/cd433f2aedeef9b1e5ed7d236c82564f7518fe7fe2238fa141ea9ce08e73; c=$(emcee-checksum)
-	elif [ $$n = entrypoints    ]; then h=b4/ef/063484f1f9ba3081e920ec9972c96664e2edb9fdc3d8669b0e3b8fc0ad7c; c=$(entrypoints-checksum)
-	elif [ $$n = esutil         ]; then h=5b/91/77e38282fd3d47b55e351544ab179eb209b309a8d2d40f8cdb6241beda00; c=$(esutil-checksum)
-	elif [ $$n = flake8         ]; then h=8d/a7/99222c9200af533c1ecb1120d99adbd1c033b57296ac5cb39d121db007a8; c=$(flake8-checksum)
-	elif [ $$n = future         ]; then h=3f/bf/57733d44afd0cf67580658507bd11d3ec629612d5e0e432beb4b8f6fbb04; c=$(future-checksum)
-	elif [ $$n = h5py           ]; then h=43/27/a6e7dcb8ae20a4dbf3725321058923fec262b6f7835179d78ccc8d98deec; c=$(h5py-checksum)
-	elif [ $$n = html5lib       ]; then h=85/3e/cf449cf1b5004e87510b9368e7a5f1acd8831c2d6691edd3c62a0823f98f; c=$(html5lib-checksum)
-	elif [ $$n = idna           ]; then h=ad/13/eb56951b6f7950cadb579ca166e448ba77f9d24efc03edd7e55fa57d04b7; c=$(idna-checksum)
-	elif [ $$n = jeepney        ]; then h=16/1d/74adf3b164a8d19a60d0fcf706a751ffa2a1eaa8e5bbb1b6705c92a05263; c=$(jeepney-checksum)
-	elif [ $$n = keyring        ]; then h=15/88/c6ce9509438bc02d54cf214923cfba814412f90c31c95028af852b19f9b2; c=$(keyring-checksum)
-	elif [ $$n = kiwisolver     ]; then h=31/60/494fcce70d60a598c32ee00e71542e52e27c978e5f8219fae0d4ac6e2864; c=$(kiwisolver-checksum)
-	elif [ $$n = lmfit          ]; then h=59/6e/117794cf85b7345361877e49245870490ae438f1981dea3c6af1316b30e7; c=$(lmfit-checksum)
-	elif [ $$n = matplotlib     ]; then h=12/d1/7b12cd79c791348cb0c78ce6e7d16bd72992f13c9f1e8e43d2725a6d8adf; c=$(matplotlib-checksum)
-	elif [ $$n = mpi4py         ]; then h=04/f5/a615603ce4ab7f40b65dba63759455e3da610d9a155d4d4cece1d8fd6706; c=$(mpi4py-checksum)
-	elif [ $$n = mpmath         ]; then h=ca/63/3384ebb3b51af9610086b23ea976e6d27d6d97bf140a76a365bd77a3eb32; c=$(mpmath-checksum)
-	elif [ $$n = numpy          ]; then h=ac/36/325b27ef698684c38b1fe2e546e2e7ef9cecd7037bcdb35c87efec4356af; c=$(numpy-checksum)
-	elif [ $$n = pexpect        ]; then h=1c/b1/362a0d4235496cb42c33d1d8732b5e2c607b0129ad5fdd76f5a583b9fcb3; c=$(pexpect-checksum)
-	elif [ $$n = pip            ]; then h=4c/4d/88bc9413da11702cbbace3ccc51350ae099bb351febae8acc85fec34f9af; c=$(pip-checksum)
-	elif [ $$n = pkgconfig      ]; then h=6e/a9/ff67ef67217dfdf2aca847685fe789f82b931a6957a3deac861297585db6; c=$(pypkgconfig-checksum)
-	elif [ $$n = pybind11       ]; then h=aa/91/deb6743e79e22ab01502296570b39b8404f10cc507a6692d612a7fee8d51; c=$(pybind11-checksum)
-	elif [ $$n = pycodestyle    ]; then h=1c/d1/41294da5915f4cae7f4b388cea6c2cd0d6cd53039788635f6875dfe8c72f; c=$(pycodestyle-checksum)
-	elif [ $$n = pycparser      ]; then h=68/9e/49196946aee219aead1290e00d1e7fdeab8567783e83e1b9ab5585e6206a; c=$(pycparser-checksum)
-	elif [ $$n = pyflakes       ]; then h=52/64/87303747635c2988fcaef18af54bfdec925b6ea3b80bcd28aaca5ba41c9e; c=$(pyflakes-checksum)
-	elif [ $$n = pyparsing      ]; then h=b9/b8/6b32b3e84014148dcd60dd05795e35c2e7f4b72f918616c61fdce83d27fc; c=$(pyparsing-checksum)
-	elif [ $$n = dateutil       ]; then h=ad/99/5b2e99737edeb28c71bcbec5b5dda19d0d9ef3ca3e92e3e925e7c0bb364c; c=$(python-dateutil-checksum)
-	elif [ $$n = requests       ]; then h=52/2c/514e4ac25da2b08ca5a464c50463682126385c4272c18193876e91f4bc38; c=$(requests-checksum)
-	elif [ $$n = scipy          ]; then h=ee/5b/5afcd1c46f97b3c2ac3489dbc95d6ca28eacf8e3634e51f495da68d97f0f; c=$(scipy-checksum)
-	elif [ $$n = secretstorage  ]; then h=a6/89/df343dbc2957a317127e7ff2983230dc5336273be34f2e1911519d85aeb5; c=$(secretstorage-checksum)
-	elif [ $$n = setuptools     ]; then h=11/0a/7f13ef5cd932a107cd4c0f3ebc9d831d9b78e1a0e8c98a098ca17b1d7d97; c=$(setuptools-checksum)
-	elif [ $$n = setuptools_scm ]; then h=83/44/53cad68ce686585d12222e6769682c4bdb9686808d2739671f9175e2938b; c=$(setuptools_scm-checksum)
-	elif [ $$n = six            ]; then h=dd/bf/4138e7bfb757de47d1f4b6994648ec67a51efe58fa907c1e11e350cddfca; c=$(six-checksum)
-	elif [ $$n = sip_tpv        ]; then h=27/93/a973aab2a3bf0c12cb385611819710921e13b090304c6bd015026cf9c502; c=$(sip_tpv-checksum)
-	elif [ $$n = soupsieve      ]; then h=0c/52/e9088bb9b96e2d39fc3b33fcda5b4fde9d71473536ac660a1ca9a0958a2f; c=$(soupsieve-checksum)
-	elif [ $$n = sympy          ]; then h=54/2e/6adb11fe599d4cfb7e8833753350ac51aa2c0603c226b36f9051cc9d2425; c=$(sympy-checksum)
-	elif [ $$n = uncertainties  ]; then h=2a/c2/babbe5b16141859dd799ed31c03987100a7b6d0ca7c0ed4429c96ce60fdf; c=$(uncertainties-checksum)
-	elif [ $$n = urllib3        ]; then h=b1/53/37d82ab391393565f2f831b8eedbffd57db5a718216f82f1a8b4d381a1c1; c=$(urllib3-checksum)
-	elif [ $$n = virtualenv     ]; then h=51/aa/c395a6e6eaaedfa5a04723b6446a1df783b16cca6fec66e671cede514688; c=$(virtualenv-checksum)
-	elif [ $$n = webencodings   ]; then h=0b/02/ae6ceac1baeda530866a85075641cec12989bd8d31af6d5ab4a3e8c92f47; c=$(webencodings-checksum)
-#	elif [ $$n = strange5-name  ]; then h=XXXXX; c=$(XXXXX-checksum)
-	else
-	  echo; echo; echo;
-	  echo "'$$n' not recognized as a dependency name to download."
-	  echo; echo; echo;
-	  exit 1
-	fi
-
-        # Download the requested tarball. Note that some packages may not
-        # follow our naming convention (where the package name is merged
-        # with its version number). In such cases, `w' will be the full
-        # address, not just the top directory address. But since we are
-        # storing all the tarballs in one directory, we want it to have
-        # the same naming convention, so we'll download it to a temporary
-        # name, then rename that.
-	rm -f "$@.unchecked"
-	if [ -f $(DEPENDENCIES-DIR)/$* ]; then
-	  cp $(DEPENDENCIES-DIR)/$* "$@.unchecked"
-	else
-	  if [ $$mergenames = 1 ]; then  tarballurl=$(pytopurl)/$$h/"$*"
-	  else                           tarballurl=$$h
-	  fi
-
-          # Download using the script specially defined for this job.
-	  touch $(lockdir)/download
-	  downloader="wget --no-use-server-timestamps -O"
-	  $(downloadwrapper) "$$downloader" $(lockdir)/download \
-	                     $$tarballurl "$@.unchecked" "$(backupservers)"
-	fi
-
-        # Make sure this is the expected tarball. Note that we now have a
-        # controlled `sha512sum' build (as part of GNU Coreutils). So we
-        # don't need to check its existance like `basic.mk'.
-	checksum=$$(sha512sum "$@.unchecked" | awk '{print $$1}')
-	if [ x"$$checksum" = x"$$c" ]; then
-	  mv "$@.unchecked" "$@"
-	else
-	  echo "ERROR: Non-matching checksum for '$*'."
-	  echo "Checksum should be: $$c"
-	  echo "Checksum is:        $$checksum"
-	  exit 1
-	fi
-
-
-
-
-
 # Necessary programs and libraries
 # --------------------------------
 #
 # While this Makefile is for Python programs, in some cases, we need
 # certain programs (like Python itself), or libraries for the modules.
-$(ibidir)/libffi: $(tdir)/libffi-$(libffi-version).tar.gz
+$(ibidir)/libffi-$(libffi-version):
+        # Prepare the source.
+	tarball=libffi-$(libffi-version).tar.gz
+	$(call import-source, $(libffi-url), $(libffi-checksum))
+
+        # Build libffi.
+	$(call gbuild, libffi-$(libffi-version), , \
+                       CFLAGS="-DNO_JAVA_RAW_API=1")
 
         # On some Fedora systems, libffi installs in `lib64', not
         # `lib'. This will cause problems when building setuptools
         # later. To fix this problem, we'll first check if this has indeed
         # happened (it exists under `lib64', but not under `lib'). If so,
         # we'll put a copy of the installed libffi libraries in `lib'.
-	$(call gbuild, libffi-$(libffi-version), , \
-                       CFLAGS="-DNO_JAVA_RAW_API=1") \
-	&& if [ -f $(idir)/lib64/libffi.a ] \
-	      && ! [ -f $(idir)/lib/libffi.a ]; then \
-	        cp $(idir)/lib64/libffi* $(ildir)/; \
-	   fi \
-	&& echo "Libffi $(libffi-version)" > $@
-
-$(ibidir)/python: $(ibidir)/libffi \
-                  $(tdir)/python-$(python-version).tar.gz
+	if [ -f $(idir)/lib64/libffi.a ] && ! [ -f $(idir)/lib/libffi.a ]; then
+	  cp $(idir)/lib64/libffi* $(ildir)/
+	fi
+	echo "Libffi $(libffi-version)" > $@
+
+$(ibidir)/python-$(python-version): $(ibidir)/libffi-$(libffi-version)
+
+        # Download the source.
+	tarball=python-$(python-version).tar.gz
+	$(call import-source, $(python-url), $(python-checksum))
+
         # On Mac systems, the build complains about `clang' specific
         # features, so we can't use our own GCC build here.
-	if [ x$(on_mac_os) = xyes ]; then \
-	  export CC=clang; \
-	  export CXX=clang++; \
-	fi; \
+	if [ x$(on_mac_os) = xyes ]; then
+	  export CC=clang
+	  export CXX=clang++
+	fi
 	$(call gbuild, Python-$(python-version),, \
 	       --without-ensurepip \
 	       --with-system-ffi \
-	       --enable-shared) \
-	&& ln -sf $(ildir)/python$(python-major-version)  $(ildir)/python \
-	&& ln -sf $(ibdir)/python$(python-major-version)  $(ibdir)/python \
-	&& ln -sf $(iidir)/python$(python-major-version)m $(iidir)/python$(python-major-version) \
-	&& rm -rf $(ipydir) \
-	&& mkdir $(ipydir) \
-	&& echo "Python $(python-version)" > $@
+	       --enable-shared, -j$(numthreads))
+	ln -sf $(ildir)/python$(python-major-version)  $(ildir)/python
+	ln -sf $(ibdir)/python$(python-major-version)  $(ibdir)/python
+	ln -sf $(iidir)/python$(python-major-version)m $(iidir)/python$(python-major-version)
+	rm -rf $(ipydir)
+	mkdir $(ipydir)
+	echo "Python $(python-version)" > $@
 
 
 
@@ -343,22 +125,22 @@ $(ibidir)/python: $(ibidir)/libffi \
 #   pyhook_before: optional steps before running `python setup.py build'
 #   pyhook_after: optional steps after running `python setup.py install'
 pybuild = cd $(ddir); rm -rf $(2); \
-	 if ! $(1) $(word 1,$(filter $(tdir)/%,$^)); then \
-	   echo; echo "Tar error"; exit 1; \
-	 fi; \
-	 cd $(2); \
-	 if [ "x$(strip $(3))" != x ]; then \
-	   sed -e 's|@LIBDIR[@]|'"$(ildir)"'|' \
-	       -e 's|@INCDIR[@]|'"$(idir)/include"'|' \
-	       $(3) > site.cfg; \
-	 fi; \
-	 if type pyhook_before &>/dev/null; then pyhook_before; fi \
-	 && python setup.py build \
-	 && python setup.py install \
-	 && if type pyhook_after &>/dev/null; then pyhook_after; fi \
-	 && cd .. \
-	 && rm -rf $(2) \
-	 && echo "$(4)" > $@
+	if ! $(1) $(tdir)/$$tarball; then \
+	  echo; echo "Tar error"; exit 1; \
+	fi; \
+	cd $(2); \
+	if [ "x$(strip $(3))" != x ]; then \
+	  sed -e 's|@LIBDIR[@]|'"$(ildir)"'|' \
+	      -e 's|@INCDIR[@]|'"$(idir)/include"'|' \
+	      $(3) > site.cfg; \
+	fi; \
+	if type pyhook_before &>/dev/null; then pyhook_before; fi; \
+	python setup.py build; \
+	python setup.py install; \
+	if type pyhook_after &>/dev/null; then pyhook_after; fi; \
+	cd ..; \
+	rm -rf $(2); \
+	echo "$(4)" > $@
 
 
 
@@ -368,31 +150,40 @@ pybuild = cd $(ddir); rm -rf $(2); \
 # ---------------
 #
 # All the necessary Python modules go here.
-$(ipydir)/asn1crypto: $(ipydir)/setuptools \
-                      $(tdir)/asn1crypto-$(asn1crypto-version).tar.gz
+$(ipydir)/asn1crypto-$(asn1crypto-version): $(ipydir)/setuptools-$(setuptools-version)
+	tarball=asn1crypto-$(asn1crypto-version).tar.gz
+	$(call import-source, $(asn1crypto-url), $(asn1crypto-checksum))
 	$(call pybuild, tar xf, asn1crypto-$(asn1crypto-version), , \
 	                Asn1crypto $(asn1crypto-version))
 
-$(ipydir)/asteval: $(ipydir)/numpy \
-                   $(tdir)/asteval-$(asteval-version).tar.gz
+$(ipydir)/asteval-$(asteval-version): $(ipydir)/numpy-$(numpy-version)
+	tarball=asteval-$(asteval-version).tar.gz
+	$(call import-source, $(asteval-url), $(asteval-checksum))
 	$(call pybuild, tar xf, asteval-$(asteval-version), , \
 	                ASTEVAL $(asteval-version))
 
-$(ipydir)/astroquery: $(ipydir)/astropy \
-                      $(ipydir)/keyring \
-                      $(ipydir)/requests \
-                      $(tdir)/astroquery-$(astroquery-version).tar.gz
-	$(call pybuild, tar xf, astroquery-$(astroquery-version), ,\
+$(ipydir)/astroquery-$(astroquery-version): \
+                     $(ipydir)/astropy-$(astropy-version) \
+                     $(ipydir)/keyring-$(keyring-version) \
+                     $(ipydir)/requests-$(requests-version)
+	tarball=astroquery-$(astroquery-version).tar.gz
+	$(call import-source, $(astroquery-url), $(astroquery-checksum))
+	$(call pybuild, tar xf, astroquery-$(astroquery-version), , \
 	                Astroquery $(astroquery-version))
 
-$(ipydir)/astropy: $(ipydir)/h5py \
-                   $(ibidir)/expat \
-                   $(ipydir)/scipy \
-                   $(ipydir)/numpy \
-                   $(ipydir)/pyyaml \
-                   $(ipydir)/html5lib \
-                   $(ipydir)/beautifulsoup4 \
-                   $(tdir)/astropy-$(astropy-version).tar.gz
+$(ipydir)/astropy-$(astropy-version): \
+                  $(ipydir)/h5py-$(h5py-version) \
+                  $(ibidir)/expat-$(expat-version) \
+                  $(ipydir)/scipy-$(scipy-version) \
+                  $(ipydir)/numpy-$(numpy-version) \
+                  $(ipydir)/pyyaml-$(pyyaml-version) \
+                  $(ipydir)/html5lib-$(html5lib-version) \
+                  $(ipydir)/beautifulsoup4-$(beautifulsoup4-version)
+
+        # Download the source.
+	tarball=astropy-$(astropy-version).tar.gz
+	$(call import-source, $(astropy-url), $(astropy-checksum))
+
         # Currently, when the Expat library is already built in a project
         # (for example as a dependency of another program), Astropy's
         # internal building of Expat will conflict with the project's. So
@@ -404,107 +195,133 @@ $(ipydir)/astropy: $(ipydir)/h5py \
 	  echo "[build]"            >> setup.cfg
 	  echo "use_system_expat=1" >> setup.cfg
 	}
-	$(call pybuild, tar xf, astropy-$(astropy-version)) \
-	&& cp $(dtexdir)/astropy.tex $(ictdir)/ \
-	&& echo "Astropy $(astropy-version) \citep{astropy2013,astropy2018}" > $@
-
-$(ipydir)/beautifulsoup4: $(ipydir)/soupsieve \
-                          $(tdir)/beautifulsoup4-$(beautifulsoup4-version).tar.gz
-	$(call pybuild, tar xf, beautifulsoup4-$(beautifulsoup4-version), ,\
+	$(call pybuild, tar xf, astropy-$(astropy-version))
+	cp $(dtexdir)/astropy.tex $(ictdir)/
+	echo "Astropy $(astropy-version) \citep{astropy2013,astropy2018}" > $@
+
+$(ipydir)/beautifulsoup4-$(beautifulsoup4-version): \
+                         $(ipydir)/soupsieve-$(soupsieve-version)
+	tarball=beautifulsoup4-$(beautifulsoup4-version).tar.gz
+	$(call import-source, $(beautifulsoup4-url), $(beautifulsoup4-checksum))
+	$(call pybuild, tar xf, beautifulsoup4-$(beautifulsoup4-version), , \
 	                BeautifulSoup $(beautifulsoup4-version))
 
-$(ipydir)/certifi: $(ipydir)/setuptools \
-                   $(tdir)/certifi-$(certifi-version).tar.gz
-	$(call pybuild, tar xf, certifi-$(certifi-version), ,\
+$(ipydir)/certifi-$(certifi-version): $(ipydir)/setuptools-$(setuptools-version)
+	tarball=certifi-$(certifi-version).tar.gz
+	$(call import-source, $(certifi-url), $(certifi-checksum))
+	$(call pybuild, tar xf, certifi-$(certifi-version), , \
 	                Certifi $(certifi-version))
 
-$(ipydir)/cffi: $(ibidir)/libffi \
-                $(ipydir)/pycparser \
-                $(tdir)/cffi-$(cffi-version).tar.gz
-	$(call pybuild, tar xf, cffi-$(cffi-version), ,\
-	                cffi $(cffi-version))
-
-$(ipydir)/chardet: $(ipydir)/setuptools \
-                   $(tdir)/chardet-$(chardet-version).tar.gz
-	$(call pybuild, tar xf, chardet-$(chardet-version), ,\
+$(ipydir)/cffi-$(cffi-version): \
+               $(ibidir)/libffi-$(libffi-version) \
+               $(ipydir)/pycparser-$(pycparser-version)
+	tarball=cffi-$(cffi-version).tar.gz
+	$(call import-source, $(cffi-url), $(cffi-checksum))
+	$(call pybuild, tar xf, cffi-$(cffi-version), ,cffi $(cffi-version))
+
+$(ipydir)/chardet-$(chardet-version): $(ipydir)/setuptools-$(setuptools-version)
+	tarball=chardet-$(chardet-version).tar.gz
+	$(call import-source, $(chardet-url), $(chardet-checksum))
+	$(call pybuild, tar xf, chardet-$(chardet-version), , \
 	                Chardet $(chardet-version))
 
-$(ipydir)/corner: $(ipydir)/matplotlib \
-                  $(tdir)/corner-$(corner-version).tar.gz
-	$(call pybuild, tar xf, corner-$(corner-version), ,\
-	                Corner $(corner-version)) \
-	&& cp $(dtexdir)/corner.tex $(ictdir)/ \
-	&& echo "Corner $(corner-version) \citep{corner}" > $@
-
-$(ipydir)/cryptography: $(ipydir)/cffi \
-                        $(ipydir)/asn1crypto \
-                        $(tdir)/cryptography-$(cryptography-version).tar.gz
-	$(call pybuild, tar xf, cryptography-$(cryptography-version), ,\
+$(ipydir)/corner-$(corner-version): $(ipydir)/matplotlib-$(matplotlib-version)
+	tarball=corner-$(corner-version).tar.gz
+	$(call import-source, $(corner-url), $(corner-checksum))
+	$(call pybuild, tar xf, corner-$(corner-version), , \
+	                Corner $(corner-version))
+	cp $(dtexdir)/corner.tex $(ictdir)/
+	echo "Corner $(corner-version) \citep{corner}" > $@
+
+$(ipydir)/cryptography-$(cryptography-version): \
+                       $(ipydir)/cffi-$(cffi-version) \
+                       $(ipydir)/asn1crypto-$(asn1crypto-version)
+	tarball=cryptography-$(cryptography-version).tar.gz
+	$(call import-source, $(cryptography-url), $(cryptography-checksum))
+	$(call pybuild, tar xf, cryptography-$(cryptography-version), , \
 	                Cryptography $(cryptography-version))
 
-$(ipydir)/cycler: $(ipydir)/six \
-                  $(tdir)/cycler-$(cycler-version).tar.gz
-	$(call pybuild, tar xf, cycler-$(cycler-version), ,\
+$(ipydir)/cycler-$(cycler-version): $(ipydir)/six-$(six-version)
+	tarball=cycler-$(cycler-version).tar.gz
+	$(call import-source, $(cycler-url), $(cycler-checksum))
+	$(call pybuild, tar xf, cycler-$(cycler-version), , \
 	                Cycler $(cycler-version))
 
-$(ipydir)/cython: $(ipydir)/setuptools \
-                  $(tdir)/cython-$(cython-version).tar.gz
-	$(call pybuild, tar xf, Cython-$(cython-version)) \
-	&& cp $(dtexdir)/cython.tex $(ictdir)/ \
-	&& echo "Cython $(cython-version) \citep{cython2011}" > $@
-
-$(ipydir)/esutil: $(ipydir)/numpy \
-                  $(tdir)/esutil-$(esutil-version).tar.gz
-	$(call pybuild, tar xf, esutil-$(esutil-version), ,\
+$(ipydir)/cython-$(cython-version): $(ipydir)/setuptools-$(setuptools-version)
+	tarball=cython-$(cython-version).tar.gz
+	$(call import-source, $(cython-url), $(cython-checksum))
+	$(call pybuild, tar xf, Cython-$(cython-version))
+	cp $(dtexdir)/cython.tex $(ictdir)/
+	echo "Cython $(cython-version) \citep{cython2011}" > $@
+
+$(ipydir)/esutil-$(esutil-version): $(ipydir)/numpy-$(numpy-version)
+	tarball=esutil-$(esutil-version).tar.gz
+	$(call import-source, $(esutil-url), $(esutil-checksum))
+	$(call pybuild, tar xf, esutil-$(esutil-version), , \
 	                esutil $(esutil-version))
 
-$(ipydir)/eigency: $(ibidir)/eigen \
-                   $(tdir)/eigency-$(eigency-version).tar.gz
-	$(call pybuild, tar xf, eigency-$(eigency-version), ,\
+$(ipydir)/eigency-$(eigency-version): \
+                  $(ipydir)/numpy-$(numpy-version) \
+                  $(ibidir)/eigen-$(eigen-version) \
+                  $(ipydir)/cython-$(cython-version)
+	tarball=eigency-$(eigency-version).tar.gz
+	$(call import-source, $(eigency-url), $(eigency-checksum))
+	$(call pybuild, tar xf, eigency-$(eigency-version), , \
 	                eigency $(eigency-version))
 
-$(ipydir)/emcee: $(ipydir)/numpy \
-                 $(ipydir)/setuptools_scm \
-                 $(tdir)/emcee-$(emcee-version).tar.gz
-	$(call pybuild, tar xf, emcee-$(emcee-version), ,\
+$(ipydir)/emcee-$(emcee-version): \
+                $(ipydir)/numpy-$(numpy-version) \
+                $(ipydir)/setuptools_scm-$(setuptools_scm-version)
+	tarball=emcee-$(emcee-version).tar.gz
+	$(call import-source, $(emcee-url), $(emcee-checksum))
+	$(call pybuild, tar xf, emcee-$(emcee-version), , \
 	                emcee $(emcee-version))
 
-$(ipydir)/entrypoints: $(ipydir)/setuptools \
-                       $(tdir)/entrypoints-$(entrypoints-version).tar.gz
-	$(call pybuild, tar xf, entrypoints-$(entrypoints-version), ,\
+$(ipydir)/entrypoints-$(entrypoints-version): \
+                      $(ipydir)/setuptools-$(setuptools-version)
+	tarball=entrypoints-$(entrypoints-version).tar.gz
+	$(call import-source, $(entrypoints-url), $(entrypoints-checksum))
+	$(call pybuild, tar xf, entrypoints-$(entrypoints-version), , \
 	                EntryPoints $(entrypoints-version))
 
-$(ipydir)/flake8: $(ipydir)/pyflakes \
-                  $(ipydir)/pycodestyle \
-                  $(tdir)/flake8-$(flake8-version).tar.gz
-	$(call pybuild, tar xf, flake8-$(flake8-version), ,\
+$(ipydir)/flake8-$(flake8-version): \
+                 $(ipydir)/pyflakes-$(pyflakes-version) \
+                 $(ipydir)/pycodestyle-$(pycodestyle-version)
+	tarball=flake8-$(flake8-version).tar.gz
+	$(call import-source, $(flake8-url), $(flake8-checksum))
+	$(call pybuild, tar xf, flake8-$(flake8-version), , \
 	                Flake8 $(flake8-version))
 
-$(ipydir)/future: $(ipydir)/setuptools \
-                  $(tdir)/future-$(future-version).tar.gz
-	$(call pybuild, tar xf, future-$(future-version), ,\
+$(ipydir)/future-$(future-version): $(ipydir)/setuptools-$(setuptools-version)
+	tarball=future-$(future-version).tar.gz
+	$(call import-source, $(future-url), $(future-checksum))
+	$(call pybuild, tar xf, future-$(future-version), , \
 	                Future $(future-version))
 
-$(ipydir)/galsim: $(ipydir)/future \
-                  $(ipydir)/astropy \
-                  $(ipydir)/eigency \
-                  $(ipydir)/pybind11 \
-                  $(ipydir)/lsstdesccoord \
-                  $(tdir)/galsim-$(galsim-version).tar.gz
-	$(call pybuild, tar xf, GalSim-$(galsim-version)) \
-	&& cp $(dtexdir)/galsim.tex $(ictdir)/ \
-	&& echo "Galsim $(galsim-version) \citep{galsim}" > $@
-
-$(ipydir)/h5py: $(ipydir)/six \
-                $(ibidir)/hdf5 \
-                $(ipydir)/numpy \
-                $(ipydir)/cython \
-                $(ipydir)/mpi4py \
-                $(ipydir)/pypkgconfig \
-                $(tdir)/h5py-$(h5py-version).tar.gz
-	export HDF5_MPI=ON; \
-	export HDF5_DIR=$(ildir); \
-	$(call pybuild, tar xf, h5py-$(h5py-version), ,\
+$(ipydir)/galsim-$(galsim-version): \
+                 $(ipydir)/future-$(future-version) \
+                 $(ipydir)/astropy-$(astropy-version) \
+                 $(ipydir)/eigency-$(eigency-version) \
+                 $(ipydir)/pybind11-$(pybind11-version) \
+                 $(ipydir)/lsstdesccoord-$(lsstdesccoord-version)
+	tarball=galsim-$(galsim-version).tar.gz
+	$(call import-source, $(galsim-url), $(galsim-checksum))
+	$(call pybuild, tar xf, GalSim-$(galsim-version))
+	cp $(dtexdir)/galsim.tex $(ictdir)/
+	echo "Galsim $(galsim-version) \citep{galsim}" > $@
+
+$(ipydir)/h5py-$(h5py-version): \
+               $(ipydir)/six-$(six-version) \
+               $(ibidir)/hdf5-$(hdf5-version) \
+               $(ipydir)/numpy-$(numpy-version) \
+               $(ipydir)/cython-$(cython-version) \
+               $(ipydir)/mpi4py-$(mpi4py-version) \
+               $(ipydir)/pypkgconfig-$(pypkgconfig-version)
+	export HDF5_MPI=ON
+	export HDF5_DIR=$(ildir)
+	tarball=h5py-$(h5py-version).tar.gz
+	$(call import-source, $(h5py-url), $(h5py-checksum))
+	$(call pybuild, tar xf, h5py-$(h5py-version), , \
 	                h5py $(h5py-version))
 
 # `healpy' is actually installed as part of the HEALPix package. It will be
@@ -514,231 +331,283 @@ $(ipydir)/h5py: $(ipydir)/six \
 # and just ask for `healpy'. To avoid confusion in such cases, we'll just
 # set `healpy' to be dependent on `healpix' and not download any tarball
 # for it, or write anything in the final target.
-$(ipydir)/healpy: $(ibidir)/healpix
+$(ipydir)/healpy-$(healpy-version): $(ibidir)/healpix-$(healpy-version)
 	touch $@
 
-$(ipydir)/html5lib: $(ipydir)/six \
-                    $(ipydir)/webencodings \
-                    $(tdir)/html5lib-$(html5lib-version).tar.gz
-	$(call pybuild, tar xf, html5lib-$(html5lib-version), ,\
+$(ipydir)/html5lib-$(html5lib-version): \
+                   $(ipydir)/six-$(six-version) \
+                   $(ipydir)/webencodings-$(webencodings-version)
+	tarball=html5lib-$(html5lib-version).tar.gz
+	$(call import-source, $(html5lib-url), $(html5lib-checksum))
+	$(call pybuild, tar xf, html5lib-$(html5lib-version), , \
 	                HTML5lib $(html5lib-version))
 
-$(ipydir)/idna: $(ipydir)/setuptools \
-                $(tdir)/idna-$(idna-version).tar.gz
-	$(call pybuild, tar xf, idna-$(idna-version), ,\
+$(ipydir)/idna-$(idna-version): $(ipydir)/setuptools-$(setuptools-version)
+	tarball=idna-$(idna-version).tar.gz
+	$(call import-source, $(idna-url), $(idna-checksum))
+	$(call pybuild, tar xf, idna-$(idna-version), , \
 	       idna $(idna-version))
 
-$(ipydir)/jeepney: $(ipydir)/setuptools \
-                   $(tdir)/jeepney-$(jeepney-version).tar.gz
-	$(call pybuild, tar xf, jeepney-$(jeepney-version), ,\
+$(ipydir)/jeepney-$(jeepney-version): $(ipydir)/setuptools-$(setuptools-version)
+	tarball=jeepney-$(jeepney-version).tar.gz
+	$(call import-source, $(jeepney-url), $(jeepney-checksum))
+	$(call pybuild, tar xf, jeepney-$(jeepney-version), , \
 	                Jeepney $(jeepney-version))
 
-$(ipydir)/keyring: $(ipydir)/entrypoints \
-                   $(ipydir)/secretstorage \
-                   $(ipydir)/setuptools_scm \
-                   $(tdir)/keyring-$(keyring-version).tar.gz
-	$(call pybuild, tar xf, keyring-$(keyring-version), ,\
+$(ipydir)/keyring-$(keyring-version): \
+                  $(ipydir)/entrypoints-$(entrypoints-version) \
+                  $(ipydir)/secretstorage-$(secretstorage-version) \
+                  $(ipydir)/setuptools_scm-$(setuptools_scm-version)
+	tarball=keyring-$(keyring-version).tar.gz
+	$(call import-source, $(keyring-url), $(keyring-checksum))
+	$(call pybuild, tar xf, keyring-$(keyring-version), , \
 	                Keyring $(keyring-version))
 
-$(ipydir)/kiwisolver: $(ipydir)/setuptools \
-                      $(tdir)/kiwisolver-$(kiwisolver-version).tar.gz
-	$(call pybuild, tar xf, kiwisolver-$(kiwisolver-version), ,\
+$(ipydir)/kiwisolver-$(kiwisolver-version): $(ipydir)/setuptools-$(setuptools-version)
+	tarball=kiwisolver-$(kiwisolver-version).tar.gz
+	$(call import-source, $(kiwisolver-url), $(kiwisolver-checksum))
+	$(call pybuild, tar xf, kiwisolver-$(kiwisolver-version), , \
 	                Kiwisolver $(kiwisolver-version))
 
-$(ipydir)/lmfit: $(ipydir)/six \
-                 $(ipydir)/scipy \
-                 $(ipydir)/emcee \
-                 $(ipydir)/corner \
-                 $(ipydir)/asteval \
-                 $(ipydir)/matplotlib \
-                 $(ipydir)/uncertainties \
-                 $(tdir)/lmfit-$(lmfit-version).tar.gz
-	$(call pybuild, tar xf, lmfit-$(lmfit-version), ,\
+$(ipydir)/lmfit-$(lmfit-version): \
+                $(ipydir)/six-$(six-version) \
+                $(ipydir)/scipy-$(scipy-version) \
+                $(ipydir)/emcee-$(emcee-version) \
+                $(ipydir)/corner-$(corner-version) \
+                $(ipydir)/asteval-$(asteval-version) \
+                $(ipydir)/matplotlib-$(matplotlib-version) \
+                $(ipydir)/uncertainties-$(uncertainties-version)
+	tarball=lmfit-$(lmfit-version).tar.gz
+	$(call import-source, $(lmfit-url), $(lmfit-checksum))
+	$(call pybuild, tar xf, lmfit-$(lmfit-version), , \
 	                LMFIT $(lmfit-version))
 
-$(ipydir)/lsstdesccoord: $(ipydir)/setuptools \
-                         $(tdir)/lsstdesccoord-$(lsstdesccoord-version).tar.gz
-	$(call pybuild, tar xf, LSSTDESC.Coord-$(lsstdesccoord-version), ,\
+$(ipydir)/lsstdesccoord-$(lsstdesccoord-version): \
+                        $(ipydir)/setuptools-$(setuptools-version)
+	tarball=lsstdesccoord-$(lsstdesccoord-version).tar.gz
+	$(call import-source, $(lsstdesccoord-url), $(lsstdesccoord-checksum))
+	$(call pybuild, tar xf, LSSTDESC.Coord-$(lsstdesccoord-version), , \
 	                LSSTDESC.Coord $(lsstdesccoord-version))
 
-$(ipydir)/matplotlib: $(ipydir)/numpy \
-                      $(ipydir)/cycler \
-                      $(itidir)/texlive \
-                      $(ibidir)/freetype \
-                      $(ipydir)/pyparsing \
-                      $(ipydir)/kiwisolver \
-                      $(ibidir)/ghostscript \
-                      $(ibidir)/imagemagick \
-                      $(ipydir)/python-dateutil \
-                      $(tdir)/matplotlib-$(matplotlib-version).tar.gz
+$(ipydir)/matplotlib-$(matplotlib-version): \
+                     $(itidir)/texlive \
+                     $(ipydir)/numpy-$(numpy-version) \
+                     $(ipydir)/cycler-$(cycler-version) \
+                     $(ibidir)/freetype-$(freetype-version) \
+                     $(ipydir)/pyparsing-$(pyparsing-version) \
+                     $(ipydir)/kiwisolver-$(kiwisolver-version) \
+                     $(ibidir)/ghostscript-$(ghostscript-version) \
+                     $(ibidir)/imagemagick-$(imagemagick-version) \
+                     $(ipydir)/python-dateutil-$(python-dateutil-version)
+
+        # Download the source.
+	tarball=matplotlib-$(matplotlib-version).tar.gz
+	$(call import-source, $(matplotlib-url), $(matplotlib-checksum))
+
         # On Mac systems, the build complains about `clang' specific
         # features, so we can't use our own GCC build here.
-	if [ x$(on_mac_os) = xyes ]; then \
-	  export CC=clang; \
-	  export CXX=clang++; \
-	fi; \
-	$(call pybuild, tar xf, matplotlib-$(matplotlib-version)) \
-	&& cp $(dtexdir)/matplotlib.tex $(ictdir)/ \
-	&& echo "Matplotlib $(matplotlib-version) \citep{matplotlib2007}" > $@
-
-$(ipydir)/mpi4py: $(ibidir)/openmpi \
-                  $(ipydir)/setuptools \
-                  $(tdir)/mpi4py-$(mpi4py-version).tar.gz
-	$(call pybuild, tar xf, mpi4py-$(mpi4py-version)) \
-	&& cp $(dtexdir)/mpi4py.tex $(ictdir)/ \
-	&& echo "mpi4py $(mpi4py-version) \citep{mpi4py2011}" > $@
-
-$(ipydir)/mpmath: $(ipydir)/setuptools \
-                  $(tdir)/mpmath-$(mpmath-version).tar.gz
-	$(call pybuild, tar xf, mpmath-$(mpmath-version), ,\
+	if [ x$(on_mac_os) = xyes ]; then
+	  export CC=clang
+	  export CXX=clang++
+	fi
+	$(call pybuild, tar xf, matplotlib-$(matplotlib-version))
+	cp $(dtexdir)/matplotlib.tex $(ictdir)/
+	echo "Matplotlib $(matplotlib-version) \citep{matplotlib2007}" > $@
+
+$(ipydir)/mpi4py-$(mpi4py-version): \
+                 $(ibidir)/openmpi-$(openmpi-version) \
+                 $(ipydir)/setuptools-$(setuptools-version)
+	tarball=mpi4py-$(mpi4py-version).tar.gz
+	$(call import-source, $(mpi4py-url), $(mpi4py-checksum))
+	$(call pybuild, tar xf, mpi4py-$(mpi4py-version))
+	cp $(dtexdir)/mpi4py.tex $(ictdir)/
+	echo "mpi4py $(mpi4py-version) \citep{mpi4py2011}" > $@
+
+$(ipydir)/mpmath-$(mpmath-version): $(ipydir)/setuptools-$(setuptools-version)
+	tarball=mpmath-$(mpmath-version).tar.gz
+	$(call import-source, $(mpmath-url), $(mpmath-checksum))
+	$(call pybuild, tar xf, mpmath-$(mpmath-version), , \
 	                mpmath $(mpmath-version))
 
-$(ipydir)/numpy: $(ibidir)/unzip \
-                 $(ibidir)/openblas \
-                 $(ipydir)/setuptools \
-                 $(tdir)/numpy-$(numpy-version).zip
-	if [ x$(on_mac_os) = xyes ]; then \
-	  export LDFLAGS="$(LDFLAGS) -undefined dynamic_lookup -bundle"; \
-	else \
-	  export LDFLAGS="$(LDFLAGS) -shared"; \
-	fi; \
-	export CFLAGS="--std=c99 $$CFLAGS"; \
-	conf="$$(pwd)/reproduce/software/config/numpy-scipy.cfg"; \
+$(ipydir)/numpy-$(numpy-version): \
+                $(ibidir)/unzip-$(unzip-version) \
+                $(ibidir)/openblas-$(openblas-version) \
+                $(ipydir)/setuptools-$(setuptools-version)
+	tarball=numpy-$(numpy-version).zip
+	$(call import-source, $(numpy-url), $(numpy-checksum))
+	if [ x$(on_mac_os) = xyes ]; then
+	  export LDFLAGS="$(LDFLAGS) -undefined dynamic_lookup -bundle"
+	else
+	  export LDFLAGS="$(LDFLAGS) -shared"
+	fi
+	export CFLAGS="--std=c99 $$CFLAGS"
+	conf="$$(pwd)/reproduce/software/config/numpy-scipy.cfg"
 	$(call pybuild, unzip, numpy-$(numpy-version),$$conf, \
-	                Numpy $(numpy-version)) \
-	&& cp $(dtexdir)/numpy.tex $(ictdir)/ \
-	&& echo "Numpy $(numpy-version) \citep{numpy2011}" > $@
-
-$(ipydir)/pexpect: $(ipydir)/setuptools \
-                   $(tdir)/pexpect-$(pexpect-version).tar.gz
-	$(call pybuild, tar xf, pexpect-$(pexpect-version), ,\
+	                Numpy $(numpy-version))
+	cp $(dtexdir)/numpy.tex $(ictdir)/
+	echo "Numpy $(numpy-version) \citep{numpy2011}" > $@
+
+$(ipydir)/pexpect-$(pexpect-version): $(ipydir)/setuptools-$(setuptools-version)
+	tarball=pexpect-$(pexpect-version).tar.gz
+	$(call import-source, $(pexpect-url), $(pexpect-checksum))
+	$(call pybuild, tar xf, pexpect-$(pexpect-version), , \
 	                Pexpect $(pexpect-version))
 
-$(ibidir)/pip3: $(ipydir)/setuptools \
-                $(tdir)/pip-$(pip-version).tar.gz
-	$(call pybuild, tar xf, pip-$(pip-version), ,\
+$(ipydir)/pip-$(pip-version): $(ipydir)/setuptools-$(setuptools-version)
+	tarball=pip-$(pip-version).tar.gz
+	$(call import-source, $(pip-url), $(pip-checksum))
+	$(call pybuild, tar xf, pip-$(pip-version), , \
 	                PiP $(pip-version))
 
-$(ipydir)/pycodestyle: $(ipydir)/setuptools \
-                       $(tdir)/pycodestyle-$(pycodestyle-version).tar.gz
-	$(call pybuild, tar xf, pycodestyle-$(pycodestyle-version), ,\
+$(ipydir)/pycodestyle-$(pycodestyle-version): \
+                      $(ipydir)/setuptools-$(setuptools-version)
+	tarball=pycodestyle-$(pycodestyle-version).tar.gz
+	$(call import-source, $(pycodestyle-url), $(pycodestyle-checksum))
+	$(call pybuild, tar xf, pycodestyle-$(pycodestyle-version), , \
 	                pycodestyle $(pycodestyle-version))
 
-$(ipydir)/pybind11: $(ibidir)/eigen \
-                    $(ibidir)/boost \
-                    $(ipydir)/setuptools \
-                    $(tdir)/pybind11-$(pybind11-version).tar.gz
+$(ipydir)/pybind11-$(pybind11-version): \
+                   $(ibidir)/eigen-$(eigen-version) \
+                   $(ibidir)/boost-$(boost-version) \
+                   $(ipydir)/setuptools-$(setuptools-version)
+	tarball=pybind11-$(pybind11-version).tar.gz
+	$(call import-source, $(pybind11-url), $(pybind11-checksum))
 	pyhook_after() {
 	  cp -r include/pybind11 $(iidir)/python$(python-major-version)m/
 	}
-	$(call pybuild, tar xf, pybind11-$(pybind11-version), ,\
+	$(call pybuild, tar xf, pybind11-$(pybind11-version), , \
 	                pybind11 $(pybind11-version))
 
-$(ipydir)/pycparser: $(ipydir)/setuptools \
-                     $(tdir)/pycparser-$(pycparser-version).tar.gz
-	$(call pybuild, tar xf, pycparser-$(pycparser-version), ,\
+$(ipydir)/pycparser-$(pycparser-version): $(ipydir)/setuptools-$(setuptools-version)
+	tarball=pycparser-$(pycparser-version).tar.gz
+	$(call import-source, $(pycparser-url), $(pycparser-checksum))
+	$(call pybuild, tar xf, pycparser-$(pycparser-version), , \
 	                pycparser $(pycparser-version))
 
-$(ipydir)/pyflakes: $(ipydir)/setuptools \
-                    $(tdir)/pyflakes-$(pyflakes-version).tar.gz
-	$(call pybuild, tar xf, pyflakes-$(pyflakes-version), ,\
+$(ipydir)/pyflakes-$(pyflakes-version): $(ipydir)/setuptools-$(setuptools-version)
+	tarball=pyflakes-$(pyflakes-version).tar.gz
+	$(call import-source, $(pyflakes-url), $(pyflakes-checksum))
+	$(call pybuild, tar xf, pyflakes-$(pyflakes-version), , \
 	                pyflakes $(pyflakes-version))
 
-$(ipydir)/pyparsing: $(ipydir)/setuptools \
-                     $(tdir)/pyparsing-$(pyparsing-version).tar.gz
-	$(call pybuild, tar xf, pyparsing-$(pyparsing-version), ,\
+$(ipydir)/pyparsing-$(pyparsing-version): $(ipydir)/setuptools-$(setuptools-version)
+	tarball=pyparsing-$(pyparsing-version).tar.gz
+	$(call import-source, $(pyparsing-url), $(pyparsing-checksum))
+	$(call pybuild, tar xf, pyparsing-$(pyparsing-version), , \
 	                PyParsing $(pyparsing-version))
 
-$(ipydir)/pypkgconfig: $(ipydir)/setuptools \
-                       $(tdir)/pkgconfig-$(pypkgconfig-version).tar.gz
+$(ipydir)/pypkgconfig-$(pypkgconfig-version): $(ipydir)/setuptools-$(setuptools-version)
+	tarball=pkgconfig-$(pypkgconfig-version).tar.gz
+	$(call import-source, $(pypkgconfig-url), $(pypkgconfig-checksum))
 	$(call pybuild, tar xf, pkgconfig-$(pypkgconfig-version), ,
 	                pkgconfig $(pypkgconfig-version))
 
-$(ipydir)/python-dateutil: $(ipydir)/six \
-                           $(ipydir)/setuptools_scm \
-                           $(tdir)/python-dateutil-$(python-dateutil-version).tar.gz
-	$(call pybuild, tar xf, python-dateutil-$(python-dateutil-version), ,\
+$(ipydir)/python-dateutil-$(python-dateutil-version): \
+                          $(ipydir)/six-$(six-version) \
+                          $(ipydir)/setuptools_scm-$(setuptools_scm-version)
+	tarball=python-dateutil-$(python-dateutil-version).tar.gz
+	$(call import-source, $(python-dateutil-url), $(python-dateutil-checksum))
+	$(call pybuild, tar xf, python-dateutil-$(python-dateutil-version), , \
 	                python-dateutil $(python-dateutil-version))
 
-$(ipydir)/pyyaml: $(ibidir)/yaml \
-                  $(ipydir)/cython \
-                  $(tdir)/pyyaml-$(pyyaml-version).tar.gz
-	$(call pybuild, tar xf, PyYAML-$(pyyaml-version), ,\
+$(ipydir)/pyyaml-$(pyyaml-version): \
+                 $(ibidir)/yaml-$(yaml-version) \
+                 $(ipydir)/cython-$(cython-version)
+	tarball=pyyaml-$(pyyaml-version).tar.gz
+	$(call import-source, $(pyyaml-url), $(pyyaml-checksum))
+	$(call pybuild, tar xf, PyYAML-$(pyyaml-version), , \
 	                PyYAML $(pyyaml-version))
 
-$(ipydir)/requests: $(ipydir)/idna \
-                    $(ipydir)/numpy \
-                    $(ipydir)/certifi \
-                    $(ipydir)/chardet \
-                    $(ipydir)/urllib3 \
-                    $(tdir)/requests-$(requests-version).tar.gz
-	$(call pybuild, tar xf, requests-$(requests-version), ,\
+$(ipydir)/requests-$(requests-version): $(ipydir)/idna-$(idna-version) \
+                    $(ipydir)/numpy-$(numpy-version) \
+                    $(ipydir)/certifi-$(certifi-version) \
+                    $(ipydir)/chardet-$(chardet-version) \
+                    $(ipydir)/urllib3-$(urllib3-version)
+	tarball=requests-$(requests-version).tar.gz
+	$(call import-source, $(requests-url), $(requests-checksum))
+	$(call pybuild, tar xf, requests-$(requests-version), , \
 	                Requests $(requests-version))
 
-$(ipydir)/scipy: $(ipydir)/numpy \
-                 $(tdir)/scipy-$(scipy-version).tar.gz
-	if [ x$(on_mac_os) = xyes ]; then \
-	  export LDFLAGS="$(LDFLAGS) -undefined dynamic_lookup -bundle"; \
-	else \
-	  export LDFLAGS="$(LDFLAGS) -shared"; \
-	fi; \
-	conf="$$(pwd)/reproduce/software/config/numpy-scipy.cfg"; \
-	$(call pybuild, tar xf, scipy-$(scipy-version),$$conf) \
-	&& cp $(dtexdir)/scipy.tex $(ictdir)/ \
-	&& echo "Scipy $(scipy-version) \citep{scipy2007,scipy2011}" > $@
-
-$(ipydir)/secretstorage: $(ipydir)/jeepney \
-                         $(ipydir)/cryptography \
-                         $(tdir)/secretstorage-$(secretstorage-version).tar.gz
-	$(call pybuild, tar xf, SecretStorage-$(secretstorage-version), ,\
+$(ipydir)/scipy-$(scipy-version): $(ipydir)/numpy-$(numpy-version)
+	tarball=scipy-$(scipy-version).tar.gz
+	$(call import-source, $(scipy-url), $(scipy-checksum))
+	if [ x$(on_mac_os) = xyes ]; then
+	  export LDFLAGS="$(LDFLAGS) -undefined dynamic_lookup -bundle"
+	else
+	  export LDFLAGS="$(LDFLAGS) -shared"
+	fi
+	conf="$$(pwd)/reproduce/software/config/numpy-scipy.cfg"
+	$(call pybuild, tar xf, scipy-$(scipy-version),$$conf)
+	cp $(dtexdir)/scipy.tex $(ictdir)/
+	echo "Scipy $(scipy-version) \citep{scipy2007,scipy2011}" > $@
+
+$(ipydir)/secretstorage-$(secretstorage-version): \
+                        $(ipydir)/jeepney-$(jeepney-version) \
+                        $(ipydir)/cryptography-$(cryptography-version)
+	tarball=secretstorage-$(secretstorage-version).tar.gz
+	$(call import-source, $(secretstorage-url), $(secretstorage-checksum))
+	$(call pybuild, tar xf, SecretStorage-$(secretstorage-version), , \
 	                SecretStorage $(secretstorage-version))
 
-$(ipydir)/setuptools: $(ibidir)/unzip \
-                      $(ibidir)/python \
-                      $(tdir)/setuptools-$(setuptools-version).zip
-	$(call pybuild, unzip, setuptools-$(setuptools-version), ,\
+$(ipydir)/setuptools-$(setuptools-version): \
+                     $(ibidir)/unzip-$(unzip-version) \
+                     $(ibidir)/python-$(python-version)
+	tarball=setuptools-$(setuptools-version).zip
+	$(call import-source, $(setuptools-url), $(setuptools-checksum))
+	$(call pybuild, unzip, setuptools-$(setuptools-version), , \
 	                Setuptools $(setuptools-version))
 
-$(ipydir)/setuptools_scm: $(ipydir)/setuptools \
-                          $(tdir)/setuptools_scm-$(setuptools_scm-version).tar.gz
-	$(call pybuild, tar xf, setuptools_scm-$(setuptools_scm-version), ,\
+$(ipydir)/setuptools_scm-$(setuptools_scm-version): \
+                         $(ipydir)/setuptools-$(setuptools-version)
+	tarball=setuptools_scm-$(setuptools_scm-version).tar.gz
+	$(call import-source, $(setuptools_scm-url), $(setuptools_scm-checksum))
+	$(call pybuild, tar xf, setuptools_scm-$(setuptools_scm-version), , \
 	                Setuptools-scm $(setuptools_scm-version))
 
-$(ipydir)/sip_tpv: $(ipydir)/sympy \
-                   $(ipydir)/astropy \
-                   $(tdir)/sip_tpv-$(sip_tpv-version).tar.gz
-	$(call pybuild, tar xf, sip_tpv-$(sip_tpv-version), ,) \
-	&& cp $(dtexdir)/sip_tpv.tex $(ictdir)/ \
-	&& echo "sip_tpv $(sip_tpv-version) \citep{sip-tpv}" > $@
+$(ipydir)/sip_tpv-$(sip_tpv-version): \
+                  $(ipydir)/sympy-$(sympy-version) \
+                  $(ipydir)/astropy-$(astropy-version)
+	tarball=sip_tpv-$(sip_tpv-version).tar.gz
+	$(call import-source, $(sip_tpv-url), $(sip_tpv-checksum))
+	$(call pybuild, tar xf, sip_tpv-$(sip_tpv-version), ,)
+	cp $(dtexdir)/sip_tpv.tex $(ictdir)/
+	echo "sip_tpv $(sip_tpv-version) \citep{sip-tpv}" > $@
 
 
-$(ipydir)/six: $(ipydir)/setuptools \
-               $(tdir)/six-$(six-version).tar.gz
-	$(call pybuild, tar xf, six-$(six-version), ,\
+$(ipydir)/six-$(six-version): $(ipydir)/setuptools-$(setuptools-version)
+	tarball=six-$(six-version).tar.gz
+	$(call import-source, $(six-url), $(six-checksum))
+	$(call pybuild, tar xf, six-$(six-version), , \
 	                Six $(six-version))
 
-$(ipydir)/soupsieve: $(ipydir)/setuptools \
-                     $(tdir)/soupsieve-$(soupsieve-version).tar.gz
-	$(call pybuild, tar xf, soupsieve-$(soupsieve-version), ,\
+$(ipydir)/soupsieve-$(soupsieve-version): $(ipydir)/setuptools-$(setuptools-version)
+	tarball=soupsieve-$(soupsieve-version).tar.gz
+	$(call import-source, $(soupsieve-url), $(soupsieve-checksum))
+	$(call pybuild, tar xf, soupsieve-$(soupsieve-version), , \
 	                SoupSieve $(soupsieve-version))
 
-$(ipydir)/sympy: $(ipydir)/mpmath \
-                 $(tdir)/sympy-$(sympy-version).tar.gz
-	$(call pybuild, tar xf, sympy-$(sympy-version), ,) \
-	&& cp $(dtexdir)/sympy.tex $(ictdir)/ \
-	&& echo "SymPy $(sympy-version) \citep{sympy}" > $@
-
-$(ipydir)/uncertainties: $(ipydir)/numpy \
-                         $(tdir)/uncertainties-$(uncertainties-version).tar.gz
-	$(call pybuild, tar xf, uncertainties-$(uncertainties-version), ,\
+$(ipydir)/sympy-$(sympy-version): $(ipydir)/mpmath-$(mpmath-version)
+	tarball=sympy-$(sympy-version).tar.gz
+	$(call import-source, $(sympy-url), $(sympy-checksum))
+	$(call pybuild, tar xf, sympy-$(sympy-version), ,)
+	cp $(dtexdir)/sympy.tex $(ictdir)/
+	echo "SymPy $(sympy-version) \citep{sympy}" > $@
+
+$(ipydir)/uncertainties-$(uncertainties-version): $(ipydir)/numpy-$(numpy-version)
+	tarball=uncertainties-$(uncertainties-version).tar.gz
+	$(call import-source, $(uncertainties-url), $(uncertainties-checksum))
+	$(call pybuild, tar xf, uncertainties-$(uncertainties-version), , \
 	                uncertainties $(uncertainties-version))
 
-$(ipydir)/urllib3: $(ipydir)/setuptools \
-                   $(tdir)/urllib3-$(urllib3-version).tar.gz
-	$(call pybuild, tar xf, urllib3-$(urllib3-version), ,\
+$(ipydir)/urllib3-$(urllib3-version): $(ipydir)/setuptools-$(setuptools-version)
+	tarball=urllib3-$(urllib3-version).tar.gz
+	$(call import-source, $(urllib3-url), $(urllib3-checksum))
+	$(call pybuild, tar xf, urllib3-$(urllib3-version), , \
 	                Urllib3 $(urllib3-version))
 
-$(ipydir)/webencodings: $(ipydir)/setuptools \
-                        $(tdir)/webencodings-$(webencodings-version).tar.gz
-	$(call pybuild, tar xf, webencodings-$(webencodings-version), ,\
+$(ipydir)/webencodings-$(webencodings-version): \
+                       $(ipydir)/setuptools-$(setuptools-version)
+	tarball=webencodings-$(webencodings-version).tar.gz
+	$(call import-source, $(webencodings-url), $(webencodings-checksum))
+	$(call pybuild, tar xf, webencodings-$(webencodings-version), , \
 	                Webencodings $(webencodings-version))
diff --git a/reproduce/software/shell/configure.sh b/reproduce/software/shell/configure.sh
index b2e3979..38dcf7f 100755
--- a/reproduce/software/shell/configure.sh
+++ b/reproduce/software/shell/configure.sh
@@ -153,6 +153,38 @@ check_permission ()
 
 
 
+# Check if there is enough free space available in the build directory
+# --------------------------------------------------------------------
+#
+# Use this function to check if there is enough free space in a
+# directory. It is meant to be passed to the 'if' statement in the
+# shell. So if there is enough space, it returns 0 (which translates to
+# TRUE), otherwise, the funcion returns 1 (which translates to FALSE).
+#
+# Expects to be called with two arguments, the first is the threshold and
+# the second is the desired directory. The 'df' function checks the given
+# path to see where it is mounted on, and how much free space there is on
+# that partition (in units of 1024 bytes).
+#
+# synopsis:
+# $ free_space_warning <acceptable_threshold> <path-to-check>
+#
+# example:
+# To check if there is 5MB of space available in /path/to/check
+# call the command with arguments as shown below:
+# $ free_space_warning 5000 /path/to/check/free/space
+free_space_warning()
+{
+    fs_threshold=$1
+    fs_destpath=$2
+    return $(df $fs_destpath \
+                | awk 'FNR==2 {if($4>'$fs_threshold') print 1; \
+                               else                   print 0; }')
+}
+
+
+
+
 
 # Check for C/C++ compilers
 # -------------------------
@@ -729,14 +761,14 @@ EOF
                 bdir=$(absolute_dir $build_dir)
                 rm -rf $build_dir/$junkname
             else
-                echo " ** Can't write in '$build_dir'"; echo
+                echo " ** Can't write in '$build_dir'";
             fi
         else
             if mkdir $build_dir 2> /dev/null; then
                 instring="the newly created"
                 bdir=$(absolute_dir $build_dir)
             else
-                echo " ** Can't create '$build_dir'"; echo
+                echo " ** Can't create '$build_dir'";
             fi
         fi
 
@@ -759,8 +791,19 @@ EOF
 	# file permissions.
 	if ! [ x"$bdir" = x ]; then
             if ! $(check_permission $bdir); then
+                # Unable to handle permissions well
                 bdir=
                 echo " ** File permissions can't be modified in this directory"
+            else
+                # Able to handle permissions, now check for 5GB free space
+                # in the given partition (note that the number is in units
+                # of 1024 bytes). If this is not the case, print a warning.
+                if $(free_space_warning 5000000 $bdir); then
+                    echo " !! LESS THAN 5GB FREE SPACE IN: $bdir"
+                    echo " !! We recommend choosing another partition."
+                    echo " !! Build will continue in 5 seconds..."
+                    sleep 5
+                fi
             fi
         fi
 
@@ -1113,7 +1156,7 @@ ln -s $instdir .local
 ln -s $texdir tex/build
 ln -s $tikzdir tex/tikz
 # --------- Delete for no Gnuastro ---------
-ln -s $topdir/reproduce/software/config/gnuastro .gnuastro
+ln -s $topdir/reproduce/analysis/config/gnuastro .gnuastro
 # ------------------------------------------
 
 
@@ -1250,6 +1293,48 @@ fi
 
 
 
+# Find Zenodo URL for software downloading
+# ----------------------------------------
+#
+# All free-software source tarballs that are potentially used in Maneage
+# are also archived in Zenodo with a certain concept-DOI. A concept-DOI is
+# a Zenodo terminology, meaning a fixed DOI of the project (that can have
+# many sub-DOIs for different versions). By default, the concept-DOI points
+# to the most recently uploaded version. However, the concept-DOI itself is
+# not directly usable for downloading files. The concept-DOI will just take
+# us to the top webpage of the most recent version of the upload.
+#
+# The problem is that as more software are added (as new Zenodo versions),
+# the most recent Zenodo-URL that the concept-DOI points to, also
+# changes. The most reliable solution was found to be the tiny script below
+# which will download the DOI-resolved webpage, and extract the Zenodo-URL
+# of the most recent version from there (using the 'coreutils' tarball as
+# an example, the directory part of the URL for all the other software are
+# the same).
+user_backup_urls=""
+zenodocheck=.build/software/zenodo-check.html
+if $downloader $zenodocheck https://doi.org/10.5281/zenodo.3883409; then
+    zenodourl=$(sed -n -e'/coreutils/p' $zenodocheck \
+                    | sed -n -e'/http/p' \
+                    | tr ' ' '\n' \
+                    | grep http \
+                    | sed -e 's/href="//' -e 's|/coreutils| |' \
+                    | awk 'NR==1{print $1}')
+else
+    zenodourl=""
+fi
+rm -f $zenodocheck
+
+# Add the Zenodo URL to the user's given back software URLs. Since the user
+# can specify 'user_backup_urls' (not yet implemented as an option in
+# './project'), we'll give preference to their specified servers, then add
+# the Zenodo URL afterwards.
+user_backup_urls="$user_backup_urls $zenodourl"
+
+
+
+
+
 # Build core tools for project
 # ----------------------------
 #
@@ -1258,7 +1343,7 @@ fi
 # (minimal Bash-like shell) and Flock (to lock files and enable serial
 # download).
 ./reproduce/software/shell/pre-make-build.sh \
-    "$bdir" "$ddir" "$downloader"
+    "$bdir" "$ddir" "$downloader" "$user_backup_urls"
 
 
 
@@ -1272,6 +1357,7 @@ fi
 # tools, but we have to be very portable (and use minimal features in all).
 echo; echo "Building necessary software (if necessary)..."
 .local/bin/make -k -f reproduce/software/make/basic.mk \
+     user_backup_urls="$user_backup_urls" \
      sys_library_path=$sys_library_path \
      rpath_command=$rpath_command \
      static_build=$static_build \
@@ -1293,20 +1379,22 @@ echo; echo "Building necessary software (if necessary)..."
 # script. Bash and Make were the tools we need to run Makefiles, so we had
 # to build them in this script. But after this, we can rely on Makefiles.
 if [ $jobs = 0 ]; then
-    numthreads=$($instdir/bin/nproc --all)
+    numthreads=$(.local/bin/nproc --all)
 else
     numthreads=$jobs
 fi
 .local/bin/env -i HOME=$bdir \
-    .local/bin/make -k -f reproduce/software/make/high-level.mk \
-                    sys_library_path=$sys_library_path \
-                    rpath_command=$rpath_command \
-                    static_build=$static_build \
-                    numthreads=$numthreads \
-                    on_mac_os=$on_mac_os \
-                    sys_cpath=$sys_cpath \
-                    host_cc=$host_cc \
-                    -j$numthreads
+     .local/bin/make -k -f reproduce/software/make/high-level.mk \
+          user_backup_urls="$user_backup_urls" \
+          sys_library_path=$sys_library_path \
+          rpath_command=$rpath_command \
+          all_highlevel=$all_highlevel \
+          static_build=$static_build \
+          numthreads=$numthreads \
+          on_mac_os=$on_mac_os \
+          sys_cpath=$sys_cpath \
+          host_cc=$host_cc \
+          -j$numthreads
 
 
 
@@ -1400,26 +1488,27 @@ prepare_name_version ()
     fi
 }
 
+# Import the context/sentences for placing between the list of software
+# names during their acknowledgment.
+. $cdir/software_acknowledge_context.sh
+
 # Report the different software in separate contexts (separating Python and
 # TeX packages from the C/C++ programs and libraries).
 proglibs=$(prepare_name_version $verdir/proglib/*)
 pymodules=$(prepare_name_version $verdir/python/*)
 texpkg=$(prepare_name_version $verdir/tex/texlive)
 
-# Write them as one paragraph for LaTeX.
+# Acknowledge these software packages in a LaTeX paragraph.
 pkgver=$mtexdir/dependencies.tex
-.local/bin/echo "This research was done with the following free" > $pkgver
-.local/bin/echo "software programs and libraries: $proglibs."   >> $pkgver
+
+# Add the text to the ${pkgver} file.
+.local/bin/echo "$thank_software_introduce " > $pkgver
+.local/bin/echo "$thank_progs_libs $proglibs. "   >> $pkgver
 if [ x"$pymodules" != x ]; then
-    .local/bin/echo "Within Python, the following modules"      >> $pkgver
-    echo "were used: $pymodules."                               >> $pkgver
+    .local/bin/echo "$thank_python $pymodules. "   >> $pkgver
 fi
-.local/bin/echo "The \LaTeX{} source of the paper was compiled" >> $pkgver
-.local/bin/echo "to make the PDF using the following packages:" >> $pkgver
-.local/bin/echo "$texpkg. We are very grateful to all their"    >> $pkgver
-.local/bin/echo "creators for freely providing this necessary"  >> $pkgver
-.local/bin/echo "infrastructure. This research (and many "      >> $pkgver
-.local/bin/echo "others) would not be possible without them."   >> $pkgver
+.local/bin/echo "$thank_latex $texpkg. " >> $pkgver
+.local/bin/echo "$thank_software_conclude" >> $pkgver
 
 # Prepare the BibTeX entries for the used software (if there are any).
 hasentry=0
diff --git a/reproduce/software/shell/pre-make-build.sh b/reproduce/software/shell/pre-make-build.sh
index e2ac789..05a4143 100755
--- a/reproduce/software/shell/pre-make-build.sh
+++ b/reproduce/software/shell/pre-make-build.sh
@@ -34,6 +34,7 @@ set -e
 bdir=$1
 ddir=$2
 downloader="$3"
+user_backup_urls="$4"
 
 
 
@@ -51,6 +52,7 @@ downloadwrapper=reproduce/analysis/bash/download-multi-try
 
 # Derived directories
 bindir=$instdir/bin
+urlfile=$confdir/urls.conf
 versionsfile=$confdir/versions.conf
 checksumsfile=$confdir/checksums.conf
 backupfile=$confdir/servers-backup.conf
@@ -65,8 +67,18 @@ export PATH="$bindir:$PATH"
 
 
 
-# Load the backup servers
-backupservers=$(awk '!/^#/{printf "%s ", $1}' $backupfile)
+# Load the backup servers, but separate the first one.
+backupservers=""
+topbackupserver=""
+maneage_backup_urls=$(awk '!/^#/{printf "%s ", $1}' $backupfile)
+backupservers_all="$user_backup_urls $maneage_backup_urls"
+for b in $backupservers_all; do
+    if [ x$topbackupserver = x ]; then
+        topbackupserver=$b
+    else
+        backupservers="$backupservers $b"
+    fi
+done
 
 
 
@@ -83,12 +95,21 @@ download_tarball() {
   else
     ucname=$tardir/$tarball.unchecked
 
+    # If the URL is empty, use the top backup server
+    if [ x$w = x ]; then
+        bservers="$backupservers"
+        tarballurl=$topbackupserver/$tarball
+    else
+        bservers="$backupservers_all"
+        tarballurl=$url/$tarball
+    fi
+
     # See if it is in the input software directory.
     if [ -f "$ddir/$tarball" ]; then
       cp $ddir/$tarball $ucname
     else
-      $downloadwrapper "$downloader" nolock $url/$tarball $ucname \
-                       "$backupservers"
+      $downloadwrapper "$downloader" nolock $tarballurl $ucname \
+                       "$bservers"
     fi
 
     # Make sure this is the correct tarball.
@@ -119,10 +140,14 @@ download_tarball() {
 
 
 
-# Build the program from the tarball
+# Build the program from the tarball. This function takes one argument
+# which is the configure-time options.
 build_program() {
   if ! [ -f $ibidir/$progname ]; then
 
+    # Options
+    configoptions=$1
+
     # Go into the temporary building directory.
     cd $tmpblddir
     unpackdir="$progname"-"$version"
@@ -140,13 +165,31 @@ build_program() {
       intar=$tardir/$tarball
     fi
 
-    # Unpack the tarball and build the program.
+    # Unpack the tarball and go into it.
     tar xf $intar
     if [ x$intarrm = x1 ]; then rm $intar; fi
     cd $unpackdir
-    ./configure --prefix=$instdir
-    make
-    make install
+
+    # build the project, either with Make and either without it.
+    if [ x$progname = xlzip ]; then
+        ./configure --build --check --installdir=$instdir/bin $configoptions
+    else
+        # All others accept the configure script.
+        ./configure --prefix=$instdir $configoptions
+
+        # To build GNU Make, we don't want to assume the existance of a
+        # Make program, so we use its 'build.sh' script and its own built
+        # 'make' program to install itself.
+        if [ x$progname = xmake ]; then
+            /bin/sh build.sh
+            ./make install
+        else
+            make
+            make install
+        fi
+    fi
+
+    # Clean up the source directory
     cd $topdir
     rm -rf $tmpblddir/$unpackdir
     echo "$progname_tex $version" > $ibidir/$progname
@@ -167,7 +210,7 @@ build_program() {
 # won't rely on the host's compression tools at all.
 progname="lzip"
 progname_tex="Lzip"
-url=http://akhlaghi.org/src
+url=$(awk '/^'$progname'-url/{print $3}' $urlfile)
 version=$(awk '/^'$progname'-version/{print $3}' $versionsfile)
 tarball=$progname-$version.tar
 download_tarball
@@ -180,19 +223,17 @@ build_program
 # GNU Make
 # --------
 #
-# The job orchestrator of Maneage is GNU Make. Although it is not
-# impossible to account for all the differences between various Make
-# implementations, its much easier (for reading the code and
-# writing/debugging it) if we can count on a special implementation. So
-# before going into the complex job orchestration in building high-level
-# software, we start by building GNU Make.
+# The job orchestrator of Maneage is GNU Make. The
+# '--disable-dependency-tracking' configure-time option is necessary so
+# Make doesn't check for an existing 'make' implementation (recall that we
+# aren't assuming any 'make' on the host).
 progname="make"
 progname_tex="GNU Make"
-url=http://akhlaghi.org/src
+url=$(awk '/^'$progname'-url/{print $3}' $urlfile)
 version=$(awk '/^'$progname'-version/{print $3}' $versionsfile)
 tarball=$progname-$version.tar.lz
 download_tarball
-build_program
+build_program --disable-dependency-tracking
 
 
 
@@ -206,7 +247,7 @@ build_program
 # (which builds GNU Bash).
 progname="dash"
 progname_tex="Dash"
-url=http://akhlaghi.org/src
+url=$(awk '/^'$progname'-url/{print $3}' $urlfile)
 version=$(awk '/^'$progname'-version/{print $3}' $versionsfile)
 tarball=$progname-$version.tar.lz
 download_tarball
@@ -235,7 +276,7 @@ fi
 # many simultaneous download commands are called.
 progname="flock"
 progname_tex="Discoteq flock"
-url=http://akhlaghi.org/src
+url=$(awk '/^'$progname'-url/{print $3}' $urlfile)
 version=$(awk '/^'$progname'-version/{print $3}' $versionsfile)
 tarball=$progname-$version.tar.lz
 download_tarball
diff --git a/reproduce/software/shell/run-parts.in b/reproduce/software/shell/run-parts.in
new file mode 100755
index 0000000..9213585
--- /dev/null
+++ b/reproduce/software/shell/run-parts.in
@@ -0,0 +1,71 @@
+#!MANEAGESHELL
+# run-parts:  Runs all the scripts found in a directory.
+# from Slackware, by Patrick J. Volkerding with ideas borrowed
+# from the Red Hat and Debian versions of this utility.
+#
+# USAGE IN MANEAGE: this script is built with the 'libpaper' package.
+#
+# The original file was taken from Linux From Scratch:
+# http://www.linuxfromscratch.org/blfs/view/svn/general/libpaper.html
+# However, it didn't have a copyright statement. So one is being added
+# here.
+#
+# Copyright (C) 2020 Authors mentioned above.
+# Copyright (C) 2020 Mohammad Akhlaghi <mohammad@akhlaghi.org>
+#
+# This script is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This script is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this script.  If not, see <http://www.gnu.org/licenses/>.
+
+# keep going when something fails
+set +e
+
+if [ $# -lt 1 ]; then
+  echo "Usage: run-parts <directory>"
+  exit 1
+fi
+
+if [ ! -d $1 ]; then
+  echo "Not a directory: $1"
+  echo "Usage: run-parts <directory>"
+  exit 1
+fi
+
+# There are several types of files that we would like to
+# ignore automatically, as they are likely to be backups
+# of other scripts:
+IGNORE_SUFFIXES="~ ^ , .bak .new .rpmsave .rpmorig .rpmnew .swp"
+
+# Main loop:
+for SCRIPT in $1/* ; do
+  # If this is not a regular file, skip it:
+  if [ ! -f $SCRIPT ]; then
+    continue
+  fi
+  # Determine if this file should be skipped by suffix:
+  SKIP=false
+  for SUFFIX in $IGNORE_SUFFIXES ; do
+    if [ ! "$(basename $SCRIPT $SUFFIX)" = "$(basename $SCRIPT)" ]; then
+      SKIP=true
+      break
+    fi
+  done
+  if [ "$SKIP" = "true" ]; then
+    continue
+  fi
+  # If we've made it this far, then run the script if it's executable:
+  if [ -x $SCRIPT ]; then
+    $SCRIPT || echo "$SCRIPT failed."
+  fi
+done
+
+exit 0
author	Mohammad Akhlaghi <mohammad@akhlaghi.org>	2020-06-27 23:49:36 +0100
committer	Mohammad Akhlaghi <mohammad@akhlaghi.org>	2020-06-27 23:49:36 +0100
commit	3d7d8cedfe0698e895949027906ce5ca996aad17 (patch)
tree	108627d6dcb039ad340e75b1b14081524cc5a3df
parent	57f922480d62a826b3e6030c81b85b412794fd4c (diff)
parent	c151eddbcc5f4208b40dc3037a8ae8adb0ff9173 (diff)