gnu: python-zulip: Do not change PYTHONPATH.

* gnu/packages/messaging.scm (python-zulip)[arguments]: Do not set PYTHONPATH
variable.

gnu: python-zulip: Remove trailing #T.

* gnu/packages/messaging.scm (python-zulip)[arguments]: Remove trailing #T
from build phases.

gnu: python-jplephem: Use ADD-INSTALLED-PYTHONPATH.

* gnu/packages/astronomy.scm (python-jplephem)[arguments]: Use
ADD-INSTALLED-PYTHONPATH instead of setting PYTHONPATH directly; run tests
conditionally.

gnu: awesome: Fix build.

* gnu/packages/patches/awesome-4.3-fno-common.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.
* gnu/packages/wm.scm (awesome)[source]: Use it.
[arguments]{set-paths}: Set HOME and XDG_CACHE_HOME variables.

gnu: moarvm: Fix compiling with gcc 10.

* gnu/packages/perl6.scm (moarvm)[arguments]: Add '-fcommon' to CFLAGS.

gnu: xfce4-screenshooter: Fix build.

* gnu/packages/xfce.scm (xfce4-screenshooter)[inputs]: Use libsoup 2.

Signed-off-by: Guillaume Le Vaillant <glv@posteo.net>

gnu: gdb: Build fix for the Hurd, part 2.

This is a follow-up to commit
    b1fd9531149b94a7e7cdabc67b08ea6a47b03d3d
    gnu: gdb: Build fix for the Hurd.

* gnu/packages/patches/gdb-fix-gnu-nat-build.patch: Include two more patches.

gnu: freecad: Use GUIX_PYTHONPATH.

* gnu/packages/engineering.scm (freecad)[arguments]: Use GUIX_PYTHONPATH.

gnu: vtk-8: Pass -fcommon to compiler.

* gnu/packages/image-processing.scm (vtk-8)[arguments]: Add -fcommon to
CFLAGS.

gnu: opencascade-occt: Use TBB 2020.

* gnu/packages/maths.scm (opencascade-occt)[inputs]: Replace tbb with
tbb-2020.

gnu: python-prawcore: Update to 7.5.0.

* gnu/packages/python-web.scm (python-prawcore): Update to 7.5.0.
[arguments]: Disable two broken tests.

gnu: python-prawcore: Update to 2.3.0.

* gnu/packages/python-web.scm (python-prawcore): Update to 2.3.0.

gnu: giara: Use libsoup2 variant of webkitgtk.

* gnu/packages/syndication.scm (giara)[inputs]: Replace webkitgtk with
webkitgtk-with-libsoup2.

gnu: giara: Use GUIX_PYTHONPATH.

* gnu/packages/syndication.scm (giara)[arguments]: Replace PYTHONPATH with
GUIX_PYTHONPATH.

gnu: python-praw: Remove trailing #T.

* gnu/packages/python-web.scm (python-praw)[arguments]: Remove trailing #T
from build phases.

gnu: python-praw: Add missing input.

* gnu/packages/python-web.scm (python-praw)[propagated-inputs]: Add
python-update-checker.

gnu: Add python-update-checker.

* gnu/packages/python-xyz.scm (python-update-checker): New variable.

gnu: python-nautilus: Remove package.

This package dates from 2016 and looks inactive.  The packages that used this
as an input actually wanted nautilus-python (not currently packaged),
for (optional) integration with the nautilus file manager.

* gnu/packages/python-xyz.scm (python-nautilus): Remove variable.
* gnu/packages/gnome-xyz.scm (gnome-shell-extension-gsconnect)[inputs]: Remove
it.
* gnu/packages/sync.scm (nexcloud-client)[inputs]: Remove it.
* gnu/packages/syncthing.scm (syncthing-gtk)[inputs]: Remove it.

Signed-off-by: Maxim Cournoyer <maxim.cournoyer@gmail.com>

gnu: python-django-localflavor: Use GUIX_PYTHONPATH.

* gnu/packages/django.scm (python-django-localflavor)[arguments]: Use
GUIX_PYTHONPATH.

gnu: python-invoke: Update to 1.6.0.

* gnu/packages/python-xyz.scm (python-invoke): Update to 1.6.0.