[FR] Tests: provide a way to point to a custom setuptools wheel

[befeleme]

What's the problem this feature will solve?

I want to update setuptools to 60.9.3 in Fedora. In our build environment there's no internet access. This means that tests using among others a newly added fixture setuptools_wheel have to be disabled, as this fixture uses module build which needs internet to install wheel. But, during the build, we create our own setuptools' wheel which could well be accessed and used by the tests.

Describe the solution you'd like

If the fixture was enhanced to first look at a customizable location (eg. by an environment variable) and if not found, proceed to the current logic, this could bypass the internet issue. As this feature could find other use cases, would you be interested in such enhancement? Do you have any suggestions about the preferred approach?

PoC working in our case:

def setuptools_wheel(tmp_path_factory, request):
    if 'LOCAL_WHEELDIR' in os.environ:
        for filename in os.listdir(os.environ['LOCAL_WHEELDIR']):
            if filename.endswith(".whl"):
                return os.path.join(os.environ['LOCAL_WHEELDIR'], filename)
    with contexts.session_locked_tmp_dir(request, tmp_path_factory, "wheel_build") as tmp:
        <snip>

Alternative Solutions

No response

Additional context

No response

Code of Conduct

• I agree to follow the PSF Code of Conduct

[abravalheri]

Hi @befeleme , thank you very much for bringing this up.

Would something like I did in the context o #3049 work for you?

setuptools/setuptools/tests/conftest.py

Lines 69 to 70 in 4b5baaa

	if os.getenv("PRE_BUILT_SETUPTOOLS_SDIST"):
	return Path(os.getenv("PRE_BUILT_SETUPTOOLS_SDIST")).resolve()

setuptools/setuptools/tests/conftest.py

Lines 86 to 87 in 4b5baaa

	if os.getenv("PRE_BUILT_SETUPTOOLS_WHEEL"):
	return Path(os.getenv("PRE_BUILT_SETUPTOOLS_WHEEL")).resolve()

[befeleme]

Hi @abravalheri, thank you, we could definitely utilize those bits in our environment! :)

[abravalheri]

Perfect, let's extract that part of the PR in a separated one.