Jason R. Coombs

Does the issue exist with pep517-isolated builds?

I was able to replicate the behavior, and setting PIP_USE_PEP517=1 dosen't work around the issue. Is that because build isolation isolates the Python environment but not the source? I thought...

@mgorny I hope you're back to health. I thought I'd check in on this PR and see if you wanted to continue with it?

It's not immediately obvious to me why this change breaks the build.

The tests are failing with the "Pre-build distributions for test" part of the CI environment with the following traceback while attempting to invoke the PEP 517 `build_wheel` hook: ``` Traceback...

I'm unable to replicate the failure in a clean docker image: ``` @ docker run -it jaraco/multipy-tox bash -c 'git clone https://github.com/pypa/setuptools; cd setuptools; git checkout feature/pep-621; pipx run --python...

Aah. The failures are in the `SETUPTOOLS_USE_DISTUTILS=stdlib` variant.

Unfortunately, I still can't replicate the issue with `docker run -it jaraco/multipy-tox bash -c 'git clone https://github.com/pypa/setuptools; cd setuptools; git checkout feature/pep-621; env SETUPTOOLS_USE_DISTUTILS=stdlib pipx run --python python3.10 --pip-args "pyproject-hooks!=1.1"...

Even running the action using `act --job test --matrix python:3.10 --matrix platform:ubuntu-latest --matrix distutils:stdlib --container-architecture linux/amd64`, the tests run. Something is peculiar about how the tests are running in GitHub.

As a shot in the dark, I tried setting the SETUPTOOLS_USE_DISTUTILS explicitly in the script and that does replicate the failure when using the `act` command above. It seems that...