[FR] Add support for PEP 794

[jenshnielsen]

What's the problem this feature will solve?

PEP 794 has been accepted but setuptools fails to build packages that contains the fields.

      Traceback (most recent call last):
        File "<string>", line 14, in <module>
          requires = get_requires_for_build({})
        File "D:\packages\uv\builds-v0\.tmptb3vmB\Lib\site-packages\setuptools\build_meta.py", line 473, in get_requires_for_build_editable
          return self.get_requires_for_build_wheel(config_settings)
                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^
        File "D:\packages\uv\builds-v0\.tmptb3vmB\Lib\site-packages\setuptools\build_meta.py", line 331, in get_requires_for_build_wheel
          return self._get_build_requires(config_settings, requirements=[])
                 ~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        File "D:\packages\uv\builds-v0\.tmptb3vmB\Lib\site-packages\setuptools\build_meta.py", line 301, in _get_build_requires
          self.run_setup()
          ~~~~~~~~~~~~~~^^
        File "D:\packages\uv\builds-v0\.tmptb3vmB\Lib\site-packages\setuptools\build_meta.py", line 317, in run_setup
          exec(code, locals())
          ~~~~^^^^^^^^^^^^^^^^
        File "<string>", line 1, in <module>
          import sys

        File "D:\packages\uv\builds-v0\.tmptb3vmB\Lib\site-packages\setuptools\__init__.py", line 115, in setup
          return distutils.core.setup(**attrs)
                 ~~~~~~~~~~~~~~~~~~~~^^^^^^^^^
        File "D:\packages\uv\builds-v0\.tmptb3vmB\Lib\site-packages\setuptools\_distutils\core.py", line 160, in setup
          dist.parse_config_files()
          ~~~~~~~~~~~~~~~~~~~~~~~^^
        File "D:\packages\uv\builds-v0\.tmptb3vmB\Lib\site-packages\_virtualenv.py", line 20, in parse_config_files
          result = old_parse_config_files(self, *args, **kwargs)
        File "D:\packages\uv\builds-v0\.tmptb3vmB\Lib\site-packages\setuptools\dist.py", line 756, in parse_config_files
          pyprojecttoml.apply_configuration(self, filename, ignore_option_errors)
          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        File "D:\packages\uv\builds-v0\.tmptb3vmB\Lib\site-packages\setuptools\config\pyprojecttoml.py", line 72, in apply_configuration
          config = read_configuration(filepath, True, ignore_option_errors, dist)
        File "D:\packages\uv\builds-v0\.tmptb3vmB\Lib\site-packages\setuptools\config\pyprojecttoml.py", line 140, in read_configuration
          validate(subset, filepath)
          ~~~~~~~~^^^^^^^^^^^^^^^^^^
        File "D:\packages\uv\builds-v0\.tmptb3vmB\Lib\site-packages\setuptools\config\pyprojecttoml.py", line 61, in validate
          raise ValueError(f"{error}\n{summary}") from None
      ValueError: invalid pyproject.toml config: `project`.
      configuration error: `project` must not contain {'import-names'} properties

      hint: This usually indicates a problem with the package or the build environment.

In the first instance this is because validate-pyproject does not yet support pep 794 see abravalheri/validate-pyproject#278

Describe the solution you'd like

Setuptools should support building correct packages with pep 794 metadata.

Alternative Solutions

• Switch to a different build backend
• Don't use this new feature

Additional context

No response

Code of Conduct

• I agree to follow the PSF Code of Conduct

[abravalheri]

Thank you for opening this discussion.

As mentioned by Henry in abravalheri/validate-pyproject#278, setuptools possibly needs to wait a little bit before the PEP is fully supported in other parts of the ecosystem (like PyPI).

When that happens we will need some volunteers to implement the part of processing the user input and then producing the relevant metadata. So I am adding a help wanted tag to this issue.

[jenshnielsen]

@abravalheri Thanks, I agree that it makes sense to wait until at least twine can upload a package with this metadata and that package can be installed by the latest version of pip without issues.

Specifically, twine upload seems to currently be blocked on pypa/packaging#950