> A PEP may be a good idea, but I do think the change doesn't have a
> particularly large magnitude. Anyone using setuptools or pip has
> already been getting setuptools' monkey-patched version of distutils
> for ages now, and soon they will be getting setuptools' vendored
> version. The documentation already indicates that distutils is at
> least soft-deprecated in favor of setuptools and we've already been
> directing issues and PRs to setuptools instead of distutils.

I don't think it's a good idea to replace bad habits from distutils with bad habits in setuptools._distutils.  And this is exactly what you get with pointing directly to setuptools.

While splitting out distutils to a separate package in a Linux distro, I found some creative usages at runtime of a package (see my lightning talk at the language summit 2018, and [1]).  From my point of view, CPython should provide documentation how to forward-port these issues without using setuptools._distutils.

Currently setuptools only has one component (pkg_resources, [2]) which is used at runtime.  I dislike it if more than that is used at runtime of a package.

[1] https://mail.python.org/archives/list/distutils-sig@python.org/thread/74WZ7D3ARF7B3N6MAV2JBV3DW6TRHFIV/
[2] https://github.com/pypa/setuptools/issues/863