[rosdep] no more distutils as of Python 3.12

[mikaelarguedas]

As per PEP 632 https://peps.python.org/pep-0632/ distutils has been deprecated from Python 3.10 and is not distributed as of Python 3.12.

The package cannot be installed on newer platforms.

Distro packaging links:

Links to Distribution Packages

This PR mark explicitly past distros as providing the package and defaults to null for all other distros.

• Debian: https://packages.debian.org/search?keywords=python3-distutils&searchon=names&suite=all&section=all
• Ubuntu: https://packages.ubuntu.com/search?keywords=python3-distutils&searchon=names&suite=all&section=all

Not sure how to deal with other distros that juste reference python standard library

[clalancette]

So, hm. I'm not sure what to do here.

For Fedora, Gentoo, and nixOS, it looks like we set this to "python" long ago (2020, it looks like). But that is actually a lie.

What I'd be in favor of here is removing all stanzas here except for the Ubuntu versions it can still be installed on, and the Debian versions it can still be installed on. That way we'll be consistent everywhere. In other words, remove fedora, gentoo, and nixos stanzas as well.

[cottsay]

But that is actually a lie.

It wasn't at the time. Python 3.11 and older provide distutils as part of the stdlib. Debian decided to pull it into a separate package for whatever reason, but that rule was right for platforms which didn't split it out.

I do however agree that platforms targeting Python >= 3.12 should drop rules now, which includes Fedora.

[cottsay]

Also note that '*': null has no effect on rosdep resolution. The only reason to include it is to serve as a hint to humans reading the rules.

[mikaelarguedas]

Also note that '*': null has no effect on rosdep resolution. The only reason to include it is to serve as a hint to humans reading the rules.

oh I forgot about that, thanks for the info!

[mikaelarguedas]

So to move forward on this I should identify which version of fedora ship what version of python and just keep the non-EOL anes and update the rules ?

not familiar with gentoo and nixOS so I may need assistance finding out what to do there

[clalancette]

It wasn't at the time. Python 3.11 and older provide distutils as part of the stdlib. Debian decided to pull it into a separate package for whatever reason, but that rule was right for platforms which didn't split it out.

I see, thanks for the info.

I do however agree that platforms targeting Python >= 3.12 should drop rules now, which includes Fedora.

Hm, though now I think it might be provided by setuptools? At least if I go on my Ubuntu 24.04 container (with Python 3.12), I can run:

$ python3.12 -c "import distutils ; print(distutils.__file__)"
/usr/lib/python3/dist-packages/setuptools/_distutils/__init__.py

[cottsay]

Hm, though now I think it might be provided by setuptools?

It might on some platforms, yes. On Fedora, a distutils-precedence.pth file is created that conditionally injects the bundled distutils from setuptools into Python's module search path. If that sort of injection happens by default, I think you could say that python3-setuptools provides this.

[nuclearsandwich]

It might on some platforms, yes. On Fedora, a distutils-precedence.pth file is created that conditionally injects the bundled distutils from setuptools into Python's module search path. If that sort of injection happens by default, I think you could say that python3-setuptools provides this.

I think we should decide whether or not we want to seamlessly transition to the setuptools shim (which will doubtless get dropped in some major version unceremoniously, possibly even in the near future) or if we think that people depending on setuptools to provide distutils should update their dependency declaration explicitly.