Project metadata in pyproject.toml vs setup.cfg

[mwtoews]

I've been seeking to move static metadata for a python project from setup.py to either setup.cfg or pyproject.toml (PEP 621), but have found that cibuildwheel does not treat these equally. Consider two pull requests for shapely:

1. Move static metadata from setup.py to pyproject.toml, add sdist check shapely/shapely#1426
2. Move static metadata from setup.py to setup.cfg, add sdist check shapely/shapely#1430

This project uses release.yml to automate binary wheels using cibuildwheel, and there have been no issues obtaining project metadata from setup.py. There also seems to be no issues with the second pull request using setup.cfg.

With the pyproject.toml approach, the trouble is in the CI section "Building wheel...":

      + rm -rf /tmp/cibuildwheel/built_wheel
      + mkdir -p /tmp/cibuildwheel/built_wheel
      + python -m pip wheel /project --wheel-dir=/tmp/cibuildwheel/built_wheel --no-deps
  Processing /project
    Installing build dependencies: started
    Installing build dependencies: finished with status 'done'
    Getting requirements to build wheel: started
    Getting requirements to build wheel: finished with status 'done'
    Installing backend dependencies: started
    Installing backend dependencies: finished with status 'done'
    Preparing metadata (pyproject.toml): started
    Preparing metadata (pyproject.toml): finished with status 'done'
  Building wheels for collected packages: UNKNOWN
    Building wheel for UNKNOWN (pyproject.toml): started
    Building wheel for UNKNOWN (pyproject.toml): finished with status 'done'
    Created wheel for UNKNOWN: filename=UNKNOWN-2.0.0.dev0+84.gb94ae9a-cp36-cp36m-linux_x86_64.whl size=769612 sha256=8f4b9965fb678844f7c053512b03c10074d9bbacd98c76db24b4485699b2ee47
    Stored in directory: /tmp/pip-ephem-wheel-cache-pww8hbhd/wheels/2e/83/83/fb24504ded536a3c91dd77593aa9037a98b0009fb86c7ebcc0
  Successfully built UNKNOWN
      + /opt/python/cp38-cp38/bin/python -c 'import sys, json, glob; json.dump(glob.glob('"'"'/tmp/cibuildwheel/built_wheel/*.whl'"'"'), sys.stdout)'
      + rm -rf /tmp/cibuildwheel/repaired_wheel
      + mkdir -p /tmp/cibuildwheel/repaired_wheel

It seems that one of the components is unable to extract the project metadata for the project name "shapely" from pyproject.toml, which is why "UNKNOWN" is shown. The dynamic data for version "2.0.0.dev0+84.gb94ae9a" was successfully obtained from setup.py (using versioneer).

Questions:

• What component is unable to get the project metadata for the project name? Is it PEP 621 compatible? If not, is there a plan to implement the feature?
• Are there obvious user errors that are blocking project metadata from pyproject.toml?
• There are no issues with setup.cfg. Is this because these components are mature?
• If there is a better forum to ask for help, please redirect me.

[henryiii]

You need setuptools 61+ for pyproject.toml. But that version doesn’t support python 3.6.

It’s the job of your build backend, not cibuildwheel, FYI. We only read Python requires and our own config. :)

[mwtoews]

It seems that wheels for 3.6 cannot be built; this appears to be the fix CIBW_SKIP: cp36-*