Disable setuptools injection in Python 3.12+ (whenever distutils gets removed from stdlib)

[pradyunsg]

What's the problem this feature will solve?

Currently, pip invokes setup.py files in a manner that injects setuptools into sys.modules; which is mainly for compatibility with projects that use distutils.setup in their setup.py files.

With distutils being deprecated and slated for removal, we should drop our compatibility shim for this.

Describe the solution you'd like

Change the logic used for make_setuptools_shim_args, to not attempt the setuptools injection for Python 3.12+ (whenever distutils gets removed).

Alternative Solutions

Do nothing. Continue performing this injection after Python 3.12+, since it'll be a no-op.

Additional context

https://pip.pypa.io/en/stable/cli/pip/#setuptools-injection for the current documentation on this.

Code of Conduct

• I agree to follow the PSF Code of Conduct.

[DiddiLeija]

Personally, I'm +1 on this. If we have time to get ready for the distutils removal, we have to use that time to detect potential errors and bugs.

Also, maybe the setuptools injection could be optional until Python 3.12 is released, but removing it as the default behavior.

[uranusjr]

Note that while distutils is scheduled for removal in 3.12, it is not guaranteed to be, and if we remove the shim without Python actually removing the module, the bare distutils.core.setup() call would do more harm than we keep the legacy path. So the removal should not happen before distutils is actually gone (i.e. weit until 3.12beta1 or so).

[pradyunsg]

This is definitely not due by the next release.

[pradyunsg]

Thinking about this a bit more, I think we shouldn't disable this until the package is removed from the standard library.

Note that while distutils is scheduled for removal in 3.12, it is not guaranteed to be, and if we remove the shim without Python actually removing the module, the bare distutils.core.setup() call would do more harm than we keep the legacy path.

True!

So the removal should not happen before distutils is actually gone (i.e. weit until 3.12beta1 or so).

And, agreed!

[hugovk]

i.e. weit until 3.12beta1 or so

The 3.12 schedule isn't published yet, but looking at the 3.11 schedule, I'd expect 3.12beta1 to be some time around May 2023.

[pradyunsg]

🙃

[pradyunsg]

@jaraco Flagging this, for your awareness. This basically involves dropping the import setuptools call in our "shim"/"caller" on Python 3.12+.

[jaraco]

At first, I was unsure why this change was associated by the distutils deprecation, because the purpose of 'import setuptools' was to trigger setuptools' monkeypatching of distutils. But then I realized that Setuptools' own distutils shim causes the monkeypatching to be present, and as a result, all uses of distutils and setuptools will get similar treatment. The one risk is that currently the setuptools shim exempts pip from the behavior, so removing the pip shim will cause projects that use "pure distutils" won't get the Setuptools treatment, so will be downgraded to simple distutils installs (even those that import distutils prior to importing setuptools). For that reason, you probably can't remove setuptools injection until setuptools nearly universally supplies distutils.