py-pip @21.3.1: should depends_run on py-wheel

[l2dy (Zero King)]

pip-3.9 install --user beets without py39-wheel would use the legacy 'setup.py install', which installs beets into the wrong directory, causing PackageNotFoundError.

Using legacy 'setup.py install' for beets, since package 'wheel' is not installed.

See also ​https://github.com/pypa/pip/issues/8368.

[jmroot (Joshua Root)]

This only affects from-source installations, right? In which case, this seems more like a dependency that should be installed when building setuptools-based projects from source (since it's not needed at all when wheels are available or when using other backends like flit or poetry), rather than a runtime dependency for pip in general. Pip is supposed to handle dependencies after all.

If pip installs into the wrong directory when using setup.py install, that also seems like a further bug. A lot of our ports still install that way and it works fine.

[l2dy (Zero King)]

As a user of pip, I'd like to get a fully functional pip command that can help me manage ~/Library/Python/3.x directories, including installing packages directly from PyPI, from-source or not.

If minimal dependencies is more important than usability, how about adding a port note that recommends installing the corresponding wheel port?