gimp: condition python2 behind new withPython argument

[fabianhjr]

Description of changes

Conditionally Python2 dep (EOLed 2020-01-01) as per #201859

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandbox = true set in nix.conf? (See Nix manual)
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 22.11 Release Notes (or backporting 22.05 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
  • (Release notes changes) Ran nixos/doc/manual/md-to-db.sh to update generated release notes
• Fits CONTRIBUTING.md.

[vcunat]

I wonder how important the python stuff is in gimp. The security issues in python2 will get fixed in nixpkgs (probably), so it might be OK to keep it here (by default).

[thiagokokada]

I wonder how important the python stuff is in gimp. The security issues in python2 will get fixed in nixpkgs (probably), so it might be OK to keep it here (by default).

I think we need to add it to the release notes for 23.05 at least.

Looking at https://bugzilla.redhat.com/show_bug.cgi?id=1737933, Python looks like necessary for a good part of the core functionality of Gimp, so yeah, disabling by default may be bad.

However, I would still go with this as-is. While I am trying to get Python 2 in a good state here in nixpkgs (see #203362 and #203428) for the use cases that I think it matters (mainly for old packages that will never be updated to work with Python 3), if we can reduce the users of Python 2, it is better.

IMO, we should work in adding Gimp 2.99.x as an option for those that want it. Gimp 2.99.x will bring both GTK3 and Python 3 support, so this would fix two of our main deprecation targets in one package. Of course, this should be done in another PR, so I am giving this one a go.

[fabianhjr]

Afaik it is used for plugins and not as common.

@jtobin might have better information.

[thiagokokada]

Afaik it is used for plugins and not as common.

@jtobin might have better information.

Arch Linux seems to ship it without support for Python, so this looks good: https://github.com/archlinux/svntogit-packages/blob/d25b5ac3e107623411b25ffde09cd74efc37c457/trunk/PKGBUILD#L50

[dotlambda]

Result of nixpkgs-review pr 203395 run on x86_64-linux 1

1 package marked as broken and skipped:

• gimpPlugins.exposureBlend

14 packages built:

• gimp (gimpPlugins.gimp)
• gimp-with-plugins
• gimpPlugins.bimp
• gimpPlugins.farbfeld
• gimpPlugins.fourier
• gimpPlugins.gap
• gimpPlugins.gimplensfun
• gimpPlugins.gmic
• gimpPlugins.lightning
• gimpPlugins.lqrPlugin
• gimpPlugins.resynthesizer
• gimpPlugins.texturize
• gimpPlugins.waveletSharpen
• toppler

[jtojnar]

Afaik it is used for plugins and not as common.

The following built-in plug-ins use Python:

• lib/gimp/2.0/plug-ins/colorxhtml/colorxhtml.py
• lib/gimp/2.0/plug-ins/file-openraster/file-openraster.py
• lib/gimp/2.0/plug-ins/foggify/foggify.py
• lib/gimp/2.0/plug-ins/gradients-save-as-css/gradients-save-as-css.py
• lib/gimp/2.0/plug-ins/histogram-export/histogram-export.py
• lib/gimp/2.0/plug-ins/palette-offset/palette-offset.py
• lib/gimp/2.0/plug-ins/palette-sort/palette-sort.py
• lib/gimp/2.0/plug-ins/palette-to-gradient/palette-to-gradient.py
• lib/gimp/2.0/plug-ins/py-slice/py-slice.py
• lib/gimp/2.0/plug-ins/python-console/python-console.py
• lib/gimp/2.0/plug-ins/python-eval/python-eval.py
• lib/gimp/2.0/plug-ins/spyro_plus/spyro_plus.py

I do not think we have any third-party Python plug-ins packaged in gimpPlugins.

IMO, we should work in adding Gimp 2.99.x as an option for those that want it. Gimp 2.99.x will bring both GTK3 and Python 3 support, so this would fix two of our main deprecation targets in one package. Of course, this should be done in another PR, so I am giving this one a go.

The unstable version is packaged in #67576

I did not want to merge it to avoid increasing maintenance burden but perhaps we have no other choice if we want to preserve those plug-ins.

[SuperSandro2000]

Why do we need the ? null here? We are not going to drop the python2 package from the tree.

#203752

[dotlambda]

We might in the future.

[SuperSandro2000]

Then we can still do this in the future or just remove the dead code.

[adisbladis]

This is a breaking change and should at least come with a release note.

[Sigmanificient]

• [Tracking issue] Removing python2 leftovers #479927