python: mark as externally managed

[SMillerDev]

• Have you followed the guidelines for contributing?
• Have you ensured that your commits follow the commit style guide?
• Have you checked that there aren't other open pull requests for the same formula update/change?
• Have you built your formula locally with brew install --build-from-source <formula>, where <formula> is the name of the formula you're submitting?
• Is your test running fine brew test <formula>, where <formula> is the name of the formula you're submitting?
• Does your build pass brew audit --strict <formula> (after doing brew install --build-from-source <formula>)? If this is a new formula, does it pass brew audit --new <formula>?

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See https://github.com/orgs/Homebrew/discussions/3404 for context

[carlocab]

autosquash Automatically squash pull request commits according to Homebrew style. ? Odd.

[carlocab]

Suggested change

	(HOMEBREW_PREFIX/"lib/python#{version.major_minor}/EXTERNALLY-MANAGED").write <<~EOS
	(site_packages/"EXTERNALLY-MANAGED").write <<~EOS

Though I think you may actually need site_packages_cellar here? Not sure. @Bo98 might know more.

[carlocab]

Also if you're writing directly to HOMEBREW_PREFIX then I think this needs to be in post_install.

[SMillerDev]

Yeah, wasn't sure about the location here. I just ended up going with the closest equivalent of upstream docs, but maybe shipping it in the Cellar is better.

[Bo98]

lib_cellar looks correct here rather than site-packages, based on the documentation that it searches stdlib.

[carlocab]

autosquash Automatically squash pull request commits according to Homebrew style. ? Odd.

Ah. Commit needs to be python@3.11: ... and not just python: ....

[Bo98]

I'm wondering whether we should hold on this until 3.12. People may have already installed system-level packages and this could break that. This is also acknowledged in the documentation:

In particular, we strongly recommend that distros with a concept of major versions only add the marker file or change sysconfig schemes in a new major version; otherwise there is a risk that, on an existing system, software installed via a Python-specific package manager now becomes unmanageable (without an override option). For a rolling-release distro, if possible, only add the marker file or change sysconfig schemes in a new Python minor version.

[carlocab]

I'm wondering whether we should hold on this until 3.12

Sounds good to me.

[Bo98]

People may have already installed system-level packages

Just to add: it appears this also blocks pip install --user as well.

[github-actions]

This pull request has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs.