Tarballs set as order-only prerequisites, not needed for build calls

Until now, the tarballs were the first normal prerequisite of the
software. As a result if their date changed, the whole software would be
re-built. However, for tarballs specifically, we actually check their
contents with a checksum, so their date is irrelevant (if its newer than
the built program, but has the same checksum, there is no need to re-build
the software).

Also, calling the tarball name as an argument to the building process (for
example `gbuild') was redundant. It is now automatically found from the
list of order-only prerequisites within `gbuild' and `cbuild' (similar to
how it was previously found in the `pybuild' for Python building).

A `README.md' file has also been placed in `reproduce/software/make' to
help describe the shared properties of the software building
Makefiles. This will hopefully grow much larger in the future.

1 files changed, 69 insertions, 64 deletions

diff --git a/reproduce/software/make/python.mk b/reproduce/software/make/python.mk
index 9b107f0..ce0c974 100644
--- a/reproduce/software/make/python.mk
+++ b/reproduce/software/make/python.mk
@@ -131,7 +131,7 @@ $(pytarballs): $(tdir)/%:
         # 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
+	@if [ $* = python-dateutil-$(python-dateutil-version).tar.gz ]; then
 	  n=dateutil
 	elif [ $* = h5py-$(h5py-version).tar.gz ]; then
 	  n=h5py
@@ -264,8 +264,10 @@ $(pytarballs): $(tdir)/%:
         # 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 '$*'."
+	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
@@ -280,14 +282,14 @@ $(pytarballs): $(tdir)/%:
 #
 # While this Makefile is for Python programs, in some cases, we need
 # certain programs (like Python itself), or libraries for the modules.
-$(ibidir)/libffi: $(tdir)/libffi-$(libffi-version).tar.gz
+$(ibidir)/libffi: | $(tdir)/libffi-$(libffi-version).tar.gz
 
         # 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), , \
+	$(call gbuild, libffi-$(libffi-version), , \
                        CFLAGS="-DNO_JAVA_RAW_API=1") \
 	&& if [ -f $(idir)/lib64/libffi.a ] \
 	      && ! [ -f $(idir)/lib/libffi.a ]; then \
@@ -296,21 +298,21 @@ $(ibidir)/libffi: $(tdir)/libffi-$(libffi-version).tar.gz
 	&& echo "Libffi $(libffi-version)" > $@
 
 $(ibidir)/python: $(ibidir)/libffi \
-                  $(tdir)/python-$(python-version).tar.gz
+                  | $(tdir)/python-$(python-version).tar.gz
         # On Mac systems, the build complains about `clang' specific
         # features, so we can't use our own GCC build here.
+	echo "HEREKJRE"; \
 	if [ x$(on_mac_os) = xyes ]; then \
 	  export CC=clang; \
 	  export CXX=clang++; \
-	fi; \
-	$(call gbuild, $(filter $(tdir)/%,$^), \
-	       Python-$(python-version),, \
+	fi; echo; echo "$@: HERE"; echo;\
+	$(call gbuild, Python-$(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) \
+	&& ln -sf $(iidir)/python$(python-major-version)m $(iidir)/python$(python-major-version) \
 	&& rm -rf $(ipydir) \
 	&& mkdir $(ipydir) \
 	&& echo "Python $(python-version)" > $@
@@ -323,7 +325,10 @@ $(ibidir)/python: $(ibidir)/libffi \
 # ----------------------------------
 #
 # To build Python packages with direct access to a `setup.py' (if no direct
-# access to `setup.py' is needed, pip can be used).
+# access to `setup.py' is needed, pip can be used). Note that the
+# software's packaged source code is the first prerequisite that is in the
+# `tdir' directory.
+#
 # Arguments of this function are the numbers
 #   1) Unpack command
 #   2) Unpacked directory name after unpacking the tarball
@@ -331,7 +336,7 @@ $(ibidir)/python: $(ibidir)/libffi \
 #   4) Official software name (for paper).
 #   5) Manual step after installation.
 pybuild = cd $(ddir); rm -rf $(2); \
-	 if ! $(1) $(filter $(tdir)/%,$^); then \
+	 if ! $(1) $(word 1,$(filter $(tdir)/%,$|)); then \
 	   echo; echo "Tar error"; exit 1; \
 	 fi; \
 	 cd $(2); \
@@ -358,12 +363,12 @@ pybuild = cd $(ddir); rm -rf $(2); \
 #
 # All the necessary Python modules go here.
 $(ipydir)/asn1crypto: $(ipydir)/setuptools \
-                      $(tdir)/asn1crypto-$(asn1crypto-version).tar.gz \
+                      | $(tdir)/asn1crypto-$(asn1crypto-version).tar.gz
 	$(call pybuild, tar xf, asn1crypto-$(asn1crypto-version), , \
 	                Asn1crypto $(asn1crypto-version))
 
 $(ipydir)/asteval: $(ipydir)/numpy \
-                   $(tdir)/asteval-$(asteval-version).tar.gz
+                   | $(tdir)/asteval-$(asteval-version).tar.gz
 	$(call pybuild, tar xf, asteval-$(asteval-version), , \
 	                ASTEVAL $(asteval-version))
 
@@ -373,41 +378,41 @@ $(ipydir)/astroquery: $(ipydir)/numpy \
                       $(ipydir)/html5lib \
                       $(ipydir)/requests \
                       $(ipydir)/beautifulsoup4 \
-                      $(tdir)/astroquery-$(astroquery-version).tar.gz
+                      | $(tdir)/astroquery-$(astroquery-version).tar.gz
 	$(call pybuild, tar xf, astroquery-$(astroquery-version), ,\
 	                Astroquery $(astroquery-version))
 
 $(ipydir)/astropy: $(ipydir)/h5py \
                    $(ipydir)/scipy \
                    $(ipydir)/numpy \
-                   $(tdir)/astropy-$(astropy-version).tar.gz
+                   | $(tdir)/astropy-$(astropy-version).tar.gz
 	$(call pybuild, tar xf, astropy-$(astropy-version)) \
 	&& cp $(dtexdir)/astropy.tex $(ictdir)/ \
 	&& echo "Astropy $(astropy-version) \citep{astropy2013,astropy2018}" > $@
 
 $(ipydir)/beautifulsoup4: $(ipydir)/soupsieve \
-                          $(tdir)/beautifulsoup4-$(beautifulsoup4-version).tar.gz
+                          | $(tdir)/beautifulsoup4-$(beautifulsoup4-version).tar.gz
 	$(call pybuild, tar xf, beautifulsoup4-$(beautifulsoup4-version), ,\
 	                BeautifulSoup $(beautifulsoup4-version))
 
 $(ipydir)/certifi: $(ipydir)/setuptools \
-                   $(tdir)/certifi-$(certifi-version).tar.gz
+                   | $(tdir)/certifi-$(certifi-version).tar.gz
 	$(call pybuild, tar xf, certifi-$(certifi-version), ,\
 	                Certifi $(certifi-version))
 
 $(ipydir)/cffi: $(ibidir)/libffi \
                 $(ipydir)/pycparser \
-                $(tdir)/cffi-$(cffi-version).tar.gz
+                | $(tdir)/cffi-$(cffi-version).tar.gz
 	$(call pybuild, tar xf, cffi-$(cffi-version), ,\
 	                cffi $(cffi-version))
 
 $(ipydir)/chardet: $(ipydir)/setuptools \
-                   $(tdir)/chardet-$(chardet-version).tar.gz
+                   | $(tdir)/chardet-$(chardet-version).tar.gz
 	$(call pybuild, tar xf, chardet-$(chardet-version), ,\
 	                Chardet $(chardet-version))
 
 $(ipydir)/corner: $(ipydir)/matplotlib \
-                  $(tdir)/corner-$(corner-version).tar.gz
+                  | $(tdir)/corner-$(corner-version).tar.gz
 	$(call pybuild, tar xf, corner-$(corner-version), ,\
 	                Corner $(corner-version)) \
 	&& cp $(dtexdir)/corner.tex $(ictdir)/ \
@@ -415,50 +420,50 @@ $(ipydir)/corner: $(ipydir)/matplotlib \
 
 $(ipydir)/cryptography: $(ipydir)/cffi \
                         $(ipydir)/asn1crypto \
-                        $(tdir)/cryptography-$(cryptography-version).tar.gz
+                        | $(tdir)/cryptography-$(cryptography-version).tar.gz
 	$(call pybuild, tar xf, cryptography-$(cryptography-version), ,\
 	                Cryptography $(cryptography-version))
 
 $(ipydir)/cycler: $(ipydir)/six \
-                  $(tdir)/cycler-$(cycler-version).tar.gz
+                  | $(tdir)/cycler-$(cycler-version).tar.gz
 	$(call pybuild, tar xf, cycler-$(cycler-version), ,\
 	                Cycler $(cycler-version))
 
 $(ipydir)/cython: $(ipydir)/setuptools \
-                  $(tdir)/cython-$(cython-version).tar.gz
+                  | $(tdir)/cython-$(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
+                  | $(tdir)/esutil-$(esutil-version).tar.gz
 	$(call pybuild, tar xf, esutil-$(esutil-version), ,\
 	                esutil $(esutil-version))
 
 $(ipydir)/eigency: $(ibidir)/eigen \
-                   $(tdir)/eigency-$(eigency-version).tar.gz
+                   | $(tdir)/eigency-$(eigency-version).tar.gz
 	$(call pybuild, tar xf, eigency-$(eigency-version), ,\
 	                eigency $(eigency-version))
 
 $(ipydir)/emcee: $(ipydir)/numpy \
                  $(ipydir)/setuptools_scm \
-                 $(tdir)/emcee-$(emcee-version).tar.gz
+                 | $(tdir)/emcee-$(emcee-version).tar.gz
 	$(call pybuild, tar xf, emcee-$(emcee-version), ,\
 	                emcee $(emcee-version))
 
 $(ipydir)/entrypoints: $(ipydir)/setuptools \
-                       $(tdir)/entrypoints-$(entrypoints-version).tar.gz
+                       | $(tdir)/entrypoints-$(entrypoints-version).tar.gz
 	$(call pybuild, tar xf, entrypoints-$(entrypoints-version), ,\
 	                EntryPoints $(entrypoints-version))
 
 $(ipydir)/flake8: $(ipydir)/pyflakes \
                   $(ipydir)/pycodestyle \
-                  $(tdir)/flake8-$(flake8-version).tar.gz
+                  | $(tdir)/flake8-$(flake8-version).tar.gz
 	$(call pybuild, tar xf, flake8-$(flake8-version), ,\
 	                Flake8 $(flake8-version))
 
 $(ipydir)/future: $(ipydir)/setuptools \
-                  $(tdir)/future-$(future-version).tar.gz
+                  | $(tdir)/future-$(future-version).tar.gz
 	$(call pybuild, tar xf, future-$(future-version), ,\
 	                Future $(future-version))
 
@@ -467,7 +472,7 @@ $(ipydir)/galsim: $(ipydir)/future \
                   $(ipydir)/eigency \
                   $(ipydir)/pybind11 \
                   $(ipydir)/lsstdesccoord \
-                  $(tdir)/galsim-$(galsim-version).tar.gz
+                  | $(tdir)/galsim-$(galsim-version).tar.gz
 	$(call pybuild, tar xf, GalSim-$(galsim-version), ,) \
 	&& cp $(dtexdir)/galsim.tex $(ictdir)/ \
 	&& echo "Galsim $(galsim-version) \citep{galsim}" > $@
@@ -478,7 +483,7 @@ $(ipydir)/h5py: $(ipydir)/six \
                 $(ipydir)/cython \
                 $(ipydir)/mpi4py \
                 $(ipydir)/pypkgconfig \
-                $(tdir)/h5py-$(h5py-version).tar.gz
+                | $(tdir)/h5py-$(h5py-version).tar.gz
 	export HDF5_MPI=ON; \
 	export HDF5_DIR=$(ildir); \
 	$(call pybuild, tar xf, h5py-$(h5py-version), ,\
@@ -496,29 +501,29 @@ $(ipydir)/healpy: $(ibidir)/healpix
 
 $(ipydir)/html5lib: $(ipydir)/six \
                     $(ipydir)/webencodings \
-                    $(tdir)/html5lib-$(html5lib-version).tar.gz
+                    | $(tdir)/html5lib-$(html5lib-version).tar.gz
 	$(call pybuild, tar xf, html5lib-$(html5lib-version), ,\
 	                HTML5lib $(html5lib-version))
 
 $(ipydir)/idna: $(ipydir)/setuptools \
-                $(tdir)/idna-$(idna-version).tar.gz
+                | $(tdir)/idna-$(idna-version).tar.gz
 	$(call pybuild, tar xf, idna-$(idna-version), ,\
 	       idna $(idna-version))
 
 $(ipydir)/jeepney: $(ipydir)/setuptools \
-                   $(tdir)/jeepney-$(jeepney-version).tar.gz \
+                   | $(tdir)/jeepney-$(jeepney-version).tar.gz \
 	$(call pybuild, tar xf, jeepney-$(jeepney-version), ,\
 	                Jeepney $(jeepney-version))
 
 $(ipydir)/keyring: $(ipydir)/entrypoints \
                    $(ipydir)/secretstorage \
                    $(ipydir)/setuptools_scm \
-                   $(tdir)/keyring-$(keyring-version).tar.gz
+                   | $(tdir)/keyring-$(keyring-version).tar.gz
 	$(call pybuild, tar xf, keyring-$(keyring-version), ,\
 	                Keyring $(keyring-version))
 
 $(ipydir)/kiwisolver: $(ipydir)/setuptools \
-                      $(tdir)/kiwisolver-$(kiwisolver-version).tar.gz
+                      | $(tdir)/kiwisolver-$(kiwisolver-version).tar.gz
 	$(call pybuild, tar xf, kiwisolver-$(kiwisolver-version), ,\
 	                Kiwisolver $(kiwisolver-version))
 
@@ -529,12 +534,12 @@ $(ipydir)/lmfit: $(ipydir)/six \
                  $(ipydir)/asteval \
                  $(ipydir)/matplotlib \
                  $(ipydir)/uncertainties \
-                 $(tdir)/lmfit-$(lmfit-version).tar.gz
+                 | $(tdir)/lmfit-$(lmfit-version).tar.gz
 	$(call pybuild, tar xf, lmfit-$(lmfit-version), ,\
 	                LMFIT $(lmfit-version))
 
 $(ipydir)/lsstdesccoord: $(ipydir)/setuptools \
-                         $(tdir)/lsstdesccoord-$(lsstdesccoord-version).tar.gz
+                         | $(tdir)/lsstdesccoord-$(lsstdesccoord-version).tar.gz
 	$(call pybuild, tar xf, LSSTDESC.Coord-$(lsstdesccoord-version), ,\
 	                LSSTDESC.Coord $(lsstdesccoord-version))
 
@@ -547,27 +552,27 @@ $(ipydir)/matplotlib: $(ipydir)/numpy \
                       $(ibidir)/ghostscript \
                       $(ibidir)/imagemagick \
                       $(ipydir)/python-dateutil \
-                      $(tdir)/matplotlib-$(matplotlib-version).tar.gz
+                      | $(tdir)/matplotlib-$(matplotlib-version).tar.gz
 	$(call pybuild, tar xf, matplotlib-$(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
+                  | $(tdir)/mpi4py-$(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
+                  | $(tdir)/mpmath-$(mpmath-version).tar.gz
 	$(call pybuild, tar xf, mpmath-$(mpmath-version), ,\
 	                mpmath $(mpmath-version))
 
 $(ipydir)/numpy: $(ibidir)/unzip \
                  $(ibidir)/openblas \
                  $(ipydir)/setuptools \
-                 $(tdir)/numpy-$(numpy-version).zip
+                 | $(tdir)/numpy-$(numpy-version).zip
 	if [ x$(on_mac_os) = xyes ]; then \
 	  export LDFLAGS="$(LDFLAGS) -undefined dynamic_lookup -bundle"; \
 	else \
@@ -580,52 +585,52 @@ $(ipydir)/numpy: $(ibidir)/unzip \
 	&& echo "Numpy $(numpy-version) \citep{numpy2011}" > $@
 
 $(ibidir)/pip3: $(ipydir)/setuptools \
-                $(tdir)/pip-$(pip-version).tar.gz
+                | $(tdir)/pip-$(pip-version).tar.gz
 	$(call pybuild, tar xf, pip-$(pip-version), ,\
 	                PiP $(pip-version))
 
 $(ipydir)/pycodestyle: $(ipydir)/setuptools \
-                       $(tdir)/pycodestyle-$(pycodestyle-version).tar.gz
+                       | $(tdir)/pycodestyle-$(pycodestyle-version).tar.gz
 	$(call pybuild, tar xf, pycodestyle-$(pycodestyle-version), ,\
 	                pycodestyle $(pycodestyle-version))
 
 $(ipydir)/pybind11: $(ibidir)/eigen \
                     $(ibidir)/boost \
                     $(ipydir)/setuptools \
-                    $(tdir)/pybind11-$(pybind11-version).tar.gz
+                    | $(tdir)/pybind11-$(pybind11-version).tar.gz
 	$(call pybuild, tar xf, pybind11-$(pybind11-version), ,\
 	                pybind11 $(pybind11-version),
 	                cp -r include/pybind11 $(iidir)/python$(python-major-version)m/)
 
 $(ipydir)/pycparser: $(ipydir)/setuptools \
-                     $(tdir)/pycparser-$(pycparser-version).tar.gz
+                     | $(tdir)/pycparser-$(pycparser-version).tar.gz
 	$(call pybuild, tar xf, pycparser-$(pycparser-version), ,\
 	                pycparser $(pycparser-version))
 
 $(ipydir)/pyflakes: $(ipydir)/setuptools \
-                    $(tdir)/pyflakes-$(pyflakes-version).tar.gz
+                    | $(tdir)/pyflakes-$(pyflakes-version).tar.gz
 	$(call pybuild, tar xf, pyflakes-$(pyflakes-version), ,\
 	                pyflakes $(pyflakes-version))
 
 $(ipydir)/pyparsing: $(ipydir)/setuptools \
-                     $(tdir)/pyparsing-$(pyparsing-version).tar.gz
+                     | $(tdir)/pyparsing-$(pyparsing-version).tar.gz
 	$(call pybuild, tar xf, pyparsing-$(pyparsing-version), ,\
 	                PyParsing $(pyparsing-version))
 
 $(ipydir)/pypkgconfig: $(ipydir)/setuptools \
-                       $(tdir)/pkgconfig-$(pypkgconfig-version).tar.gz
+                       | $(tdir)/pkgconfig-$(pypkgconfig-version).tar.gz
 	$(call pybuild, tar xf, pkgconfig-$(pypkgconfig-version), ,
 	                pkgconfig $(pypkgconfig-version))
 
 $(ipydir)/python-dateutil: $(ipydir)/six \
                            $(ipydir)/setuptools_scm \
-                           $(tdir)/python-dateutil-$(python-dateutil-version).tar.gz
+                           | $(tdir)/python-dateutil-$(python-dateutil-version).tar.gz
 	$(call pybuild, tar xf, python-dateutil-$(python-dateutil-version), ,\
 	                python-dateutil $(python-dateutil-version))
 
 $(ipydir)/pyyaml: $(ibidir)/yaml \
                   $(ipydir)/cython \
-                  $(tdir)/pyyaml-$(pyyaml-version).tar.gz
+                  | $(tdir)/pyyaml-$(pyyaml-version).tar.gz
 	$(call pybuild, tar xf, PyYAML-$(pyyaml-version), ,\
 	                PyYAML $(pyyaml-version))
 
@@ -634,12 +639,12 @@ $(ipydir)/requests: $(ipydir)/idna \
                     $(ipydir)/certifi \
                     $(ipydir)/chardet \
                     $(ipydir)/urllib3 \
-                    $(tdir)/requests-$(requests-version).tar.gz
+                    | $(tdir)/requests-$(requests-version).tar.gz
 	$(call pybuild, tar xf, requests-$(requests-version), ,\
 	                Requests $(requests-version))
 
 $(ipydir)/scipy: $(ipydir)/numpy \
-                 $(tdir)/scipy-$(scipy-version).tar.gz
+                 | $(tdir)/scipy-$(scipy-version).tar.gz
 	if [ x$(on_mac_os) = xyes ]; then \
 	  export LDFLAGS="$(LDFLAGS) -undefined dynamic_lookup -bundle"; \
 	else \
@@ -652,56 +657,56 @@ $(ipydir)/scipy: $(ipydir)/numpy \
 
 $(ipydir)/secretstorage: $(ipydir)/jeepney \
                          $(ipydir)/cryptography \
-                         $(tdir)/secretstorage-$(secretstorage-version).tar.gz
+                         | $(tdir)/secretstorage-$(secretstorage-version).tar.gz
 	$(call pybuild, tar xf, SecretStorage-$(secretstorage-version), ,\
 	                SecretStorage $(secretstorage-version))
 
 $(ipydir)/setuptools: $(ibidir)/unzip \
                       $(ibidir)/python \
-                      $(tdir)/setuptools-$(setuptools-version).zip
+                      | $(tdir)/setuptools-$(setuptools-version).zip
 	$(call pybuild, unzip, setuptools-$(setuptools-version), ,\
 	                Setuptools $(setuptools-version))
 
 $(ipydir)/setuptools_scm: $(ipydir)/setuptools \
-                          $(tdir)/setuptools_scm-$(setuptools_scm-version).tar.gz
+                          | $(tdir)/setuptools_scm-$(setuptools_scm-version).tar.gz
 	$(call pybuild, tar xf, setuptools_scm-$(setuptools_scm-version), ,\
 	                Setuptools-scm $(setuptools_scm-version))
 
 $(ipydir)/sip_tpv: $(ipydir)/sympy \
                    $(ipydir)/astropy \
-                   $(tdir)/sip_tpv-$(sip_tpv-version).tar.gz
+                   | $(tdir)/sip_tpv-$(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)/six: $(ipydir)/setuptools \
-               $(tdir)/six-$(six-version).tar.gz
+               | $(tdir)/six-$(six-version).tar.gz
 	$(call pybuild, tar xf, six-$(six-version), ,\
 	                Six $(six-version))
 
 $(ipydir)/soupsieve: $(ipydir)/setuptools \
-                     $(tdir)/soupsieve-$(soupsieve-version).tar.gz
+                     | $(tdir)/soupsieve-$(soupsieve-version).tar.gz
 	$(call pybuild, tar xf, soupsieve-$(soupsieve-version), ,\
 	                SoupSieve $(soupsieve-version))
 
 $(ipydir)/sympy: $(ipydir)/mpmath \
-                 $(tdir)/sympy-$(sympy-version).tar.gz
+                 | $(tdir)/sympy-$(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
+                         | $(tdir)/uncertainties-$(uncertainties-version).tar.gz
 	$(call pybuild, tar xf, uncertainties-$(uncertainties-version), ,\
 	                uncertainties $(uncertainties-version))
 
 $(ipydir)/urllib3: $(ipydir)/setuptools \
-                   $(tdir)/urllib3-$(urllib3-version).tar.gz
+                   | $(tdir)/urllib3-$(urllib3-version).tar.gz
 	$(call pybuild, tar xf, urllib3-$(urllib3-version), ,\
 	                Urllib3 $(urllib3-version))
 
 $(ipydir)/webencodings: $(ipydir)/setuptools \
-                        $(tdir)/webencodings-$(webencodings-version).tar.gz
+                        | $(tdir)/webencodings-$(webencodings-version).tar.gz
 	$(call pybuild, tar xf, webencodings-$(webencodings-version), ,\
 	                Webencodings $(webencodings-version))