[bug#74715] Request for merging "python-team" branch

[Lars-Dominik Braun]

Hi Ian,

> Since this merge landed, the builds for several Python packages in my 
> personal channel broke.  Any package using pyproject-build-system for a 
> Python project using setuptools seems to be affected.

as Sharlatan Hellseher wrote in https://issues.guix.gnu.org/issue/74715#4,
you need to add python-setuptools and python-wheel to your
setuptools-based packages. The default python toolchain used by
pyproject-build-system (python-sans-pip-wrapper from
gnu/packages/python.scm) does not include these packages any more,
since they are technically not required and declaring them as *real*
inputs allows using different versions of these packages more easily
for packages, which require them. Plus there are quite a few packages,
which build using different build systems nowadays.

The python importer should probably be updated to read pyproject.toml
and parse the [build-system] table (there is a toml parser in Guix now,
so this should be easy).

Lars