How to specify a specific package version to CIBW_TEST_REQUIRES for Windows

[bhazelton]

We've been using cibuildwheel very successfully for some time, it's wonderful! But a new problem just came up on windows builds because we need to limit pytest to <8.0 for now. The following is working on linux & mac builds but failing on windows:

CIBW_TEST_REQUIRES: packaging pytest<8.0 pytest-cov pytest-cases

On Windows it generates an error: The system cannot find the file specified.

The relevant section of the build log is:

  + pip install packaging 'pytest<8.0' pytest-cov pytest-cases
  The system cannot find the file specified.
Error: Command ['pip', 'install', 'packaging', 'pytest<8.0', 'pytest-cov', 'pytest-cases'] failed with code 1. None

How should the version specification be done to work on Windows (as well as linux and mac)? I've tried adding quotes and quotes with a space between the package and version specification, neither worked.

Thanks for the package and the help!!

CI link: https://github.com/RadioAstronomySoftwareGroup/pyuvdata/actions/runs/7732465269/job/21082460054

workflow link: https://github.com/RadioAstronomySoftwareGroup/pyuvdata/blob/always-slicify/.github/workflows/publish-to-test-pypi.yaml

[ymd-h]

Escape < by ^.

CIBW_TEST_REQUIRES: packaging pytest^<8.0 pytest-cov pytest-cases

---

I also struggled this problem, and finally solved it.
ymd-h/cpprb@b1a2bfd

On Windows, cibuildwheel executes sub command through shell (aka. cmd).

cibuildwheel/cibuildwheel/util.py

Lines 154 to 162 in 9c75ea1

	result = subprocess.run(
	args_,
	check=True,
	shell=IS_WIN,
	env=env,
	cwd=cwd,
	capture_output=capture_stdout,
	text=capture_stdout,
	)

And cmd requires to escape < character by ^.

Unfortunately, this is (probably) incompatible with Linux and macOS,
so that we might have to use configuration overrides or to use different environment variables depending OS.
https://cibuildwheel.pypa.io/en/stable/options/#overrides

---

I am not sure whether this escape should be handled by cibuildwheel or user.
If cibuildwheel escape these special characters internally, we can use same setting on both Windows and non-Windows,
however, it will introduce backward incompatibility. (It will break already escaped settings.)