[python-setuptools] --plat-name must be one of ('win32', 'win-amd64', 'win-arm32', 'win-arm64')

[radarhere]

Description / Steps to reproduce the issue

I've created a branch at https://github.com/radarhere/Pillow/tree/setuptools_mingw_demo that demonstrates the error with GitHub Actions, from a simple Python script and relatively simple C script.

Expected behavior

At least not the error that I received.

If I've made a mistake in trying to create a simple demonstration, let me know.

Actual behavior

https://github.com/radarhere/Pillow/actions/runs/4860227968/jobs/8663795736#step:5:28

error: --plat-name must be one of ('win32', 'win-amd64', 'win-arm32', 'win-arm64')

Googling, I found the error at pypa/pip#11258, where it was suggested that this is a package problem, not a problem with setuptools.

Verification

• I have verified that my MSYS2 is up-to-date before submitting the report (see https://www.msys2.org/docs/updating/)

Windows Version

MINGW64_NT-10.0-20348

MINGW environments affected

• MINGW64
• MINGW32
• UCRT64
• CLANG64
• CLANG32
• CLANGARM64

Are you willing to submit a PR?

No response

[Biswa96]

There is some known issues about incompatibility between mingw python and regular python for Windows. MOre info here https://www.msys2.org/docs/python/. Try to use the mingw python packages only.

[radarhere]

I believe I am only using the MinGW Python packages, as if I don't install mingw-w64-x86_64-python3-pip, I get an error that pip is missing.

However, looking at that link, I noticed

setuptools >= 60.0 is currently incompatible with MSYS2. You can set export SETUPTOOLS_USE_DISTUTILS=stdlib to work around the issue. We are currently working on restoring compatibility.

And adding that setting solves the problem! Thanks very much.