> A recent post to the wheel-builders mailing list pointed out some
> links to places providing free PowerPC hosting for open source
> projects, if they agree to a submitted request:

The debian project has some powerpc machines (and we still build numpy
on those boxes when i upload a new revision to our archives) and they
also have hosts dedicated to let debian developers login and debug
issues with their packages on that architecture. I can sponsor access
to those machines for some of you, but it is not a place where you can
host a CI instance.

Just keep it in mind more broadly than powerpc, f.e. these are all the
archs where numpy was built after the last upload
https://buildd.debian.org/status/package.php?p=python-numpy&suite=unstable
(the grayed out archs are the ones non release critical, so packages
are built as best effort and if missing is not a big deal)