Use of pkg_resources is deprecated

[hosiet]

When building the python wheel package, the following DeprecationWarning is emitted:

python3.12 -m build --skip-dependency-check --no-isolation --wheel
* Building wheel...
<string>:7: DeprecationWarning: pkg_resources is deprecated as an API. See https://setuptools.pypa.io/en/latest/pkg_resources.html

I see that setup.py imported pkg_resources. Please consider migrating away from it.

[musicinmybrain]

Just analyzing this a bit as someone who is packaging this for Fedora, and has worked on some related packages, but doesn’t regularly contribute to upstream development.

Here’s how pkg_resources is used:

openstep-plist/setup.py

Lines 26 to 32 in 61dc6ac

	try:
	required_cython = "cython >= %s" % cython_min_version
	pkg_resources.require(required_cython)
	except pkg_resources.ResolutionError:
	with_cython = False
	else:
	with_cython = True

Directly replacing it without changing what it does is not straighforward: pypa/packaging-problems#317

On the other hand, there are many different styles of dealing with building Cython packages with or without regenerating sources; https://github.com/MagicStack/asyncpg/blob/v0.30.0/setup.py is an example of a different, perhaps somewhat fussy but effective approach.

This use of pkg_resources is only in a single spot setup.py, not in the library itself, so there probably doesn’t need to be a big hurry to replace it as long as setuptools still ships pkg_resources. If @anthrotype does settle on a different approach at some point, I assume they will want to make it consistent across all their Cython-based projects, e.g. https://github.com/googlefonts/compreffor/blob/0.5.6/setup.py and various others with similar snippets.