gnu: python2-virtualenv: Fix build.

* gnu/packages/python-xyz.scm (python2-virtualenv)[arguments]{phases}: Remove
argument.

gnu: python2-packaging-bootstrap: Add missing dependency

* gnu/packages/python-xyz.scm (python2-packaging-bootstrap)
[propagated-inputs]: Add python2-six-bootstrap.

gnu: python-traceback2: Add missing dependency.

* gnu/packages/python-xyz.scm (python-traceback2)[propagated-inputs]:
Add python-six.

gnu: python-packaging-bootstrap: Remove dependency.

* gnu/packages/python-xyz.scm (python-packaging-bootstrap) [arguments]:
Remove dependency from setup.py, which we do not provide for this
variant.

gnu: python-automat: Remove broken console script.

* gnu/packages/python-xyz.scm (python-automat) [arguments]: Patch
setup.py.

gnu: python-twisted: Remove broken console scripts.

* gnu/packages/python-xyz.scm (python-twisted) [arguments]: Patch
setup.py.

gnu: python-idna-ssl: Add missing input.

* gnu/packages/python-xyz.scm (python-idna-ssl)[propagated-inputs]: Add
python-idna.

gnu: python-traitlets: Add missing input.

* gnu/packages/python-xyz.scm (python-traitlets)[propagated-inputs]:
Add python-six.

gnu: python-black: Remove blackd.

* gnu/packages/python-xyz.scm (python-black) [arguments]: Add new phase
to prevent installation of blackd.

gnu: Replace all uses of texlive-union by texlive-updmap.cfg.

* doc/build.scm (pdf-manual) Replace texlive-union by texlive-updmap.cfg.
* gnu/packages/algebra.scm (pari-gp): Likewise.
* gnu/packages/bioinformatics.scm (discrover, velvet): Likewise.
* gnu/packages/chez.scm (chez-scheme, chez-web, chez-sockets): Likewise.
* gnu/packages/docbook.scm (dblatex): Likewise.
* gnu/packages/emacs-xyz.scm (emacs-auctex): Likewise.
* gnu/packages/engineering.scm (fastcap): Likewise.
* gnu/packages/guile-xyz.scm (emacsy, guile-cv): Likewise.
* gnu/packages/lisp.scm (sbcl): Likewise.
* gnu/packages/maths.scm (octave, hypre): Likewise.
* gnu/packages/music.scm (lilypond): Likewise.
* gnu/packages/plotutils.scm (asymptote): Likewise.
* gnu/packages/python-xyz.scm (python-numpy-documentation)
(python-matplotlib-documentation, python-ipython-documentation)
(python-pypandoc): Likewise.
* gnu/packages/radio.scm (gnuradio, libosmo-dsp): Likewise.
* gnu/packages/scheme.scm (mit-scheme): Likewise.
* gnu/packages/statistics.scm (r-with-tests): Likewise.
* gnu/packages/tex.scm (simple-texlive-package)
(texlive-xmltex, texlive-tiny, texlive-jadetex, teximpatient, lyx): Likewise.

gnu: python-setuptools-scm: Update to 5.0.1.

* gnu/packages/python-xyz.scm (python-setuptools-scm): Update to 5.0.1.

gnu: python-isort: Update to 5.7.0, fixing build on Python 3.9.

* gnu/packages/python-xyz.scm (python-isort): Update to 5.7.0.
[source]: Delete checked in binary wheels in a snippet.
[arguments]: New field.
[phases]: Replace the build and install phases, implementing the basics of a
PEP 517 build system.
{check}: Override phase.
{install-example-plugins}: New phase.
[native-inputs]: Remove python-mock.  Add git-minimal, python-black,
python-colorama, python-hypothesmith, python-libcst-minimal,
python-poetry-core, python-pylama, python-pypa-build and python-pytest-mock.
[home-page]: Update home page.

gnu: python2-isort: Remove package.

* gnu/packages/python-xyz.scm (python-isort)[properties]: Remove field.
(python2-isort): Delete variable.

gnu: python2-factory-boy: Remove package.

* gnu/packages/python-xyz.scm (python2-factory-boy): Remove variable.

gnu: python-typing-inspect: Fix build on Python 3.9.

* gnu/packages/patches/python-typing-inspect-fix.patch: Add patch.
* gnu/local.mk (dist_patch_DATA): Register it.
* gnu/packages/python-xyz.scm (python-typing-inspect)[patches]: Apply it.

gnu: Add python-libcst-minimal.

* gnu/packages/python-xyz.scm (python-libcst-minimal): New variable.
(python-libcst): Add a tests? argument to the check phase override and strip
trailing #t.

gnu: python-virtualenv: Update to 20.3.1.

* gnu/packages/python-xyz.scm (python-virtualenv): Update to 20.3.1.
[propagated-inputs]: Remove setuptools and python-importlib-metadata.

gnu: python-flake8-pyi: Update to 20.10.0.

* gnu/packages/python-xyz.scm (python-flake8-pyi): Update to 20.10.0.

gnu: python-backpack: Fix build.

* gnu/packages/python-xyz.scm (python-backpack)[native-inputs]: Add python-toml.

gnu: python-simplejson: Update to 3.17.2, fixing build.

* gnu/packages/python-xyz.scm (python-simplejson): Update to 3.17.2.
[native-inputs]: Add python-toml.