Re: [PATCH v2 0/7] Python: Drop support for Python 3.6

[Markus Armbruster <armbru@redhat.com>]

The discussion under PATCH 6 makes me think there's a bit of confusion
about the actual impact of dropping support for Python 3.6.  Possibly
because it's spelled out in the commit message of PATCH 7.  Let me
summarize it in one sentence:

    *** All supported host systems continue to work ***

Evidence: CI remains green.

On some supported host systems, different packages need to be installed.
On CentOS 8, for instance, we need to install Python 3.8.13 or 3.9.16
instead of 3.6.8.  Let me stress again: same repository, different
package.  No downsides I can see.

The *one* exception is Sphinx on CentOS 8.  CentOS 8 does not ship a
version of Sphinx that works with Python 3.7 or newer.  This series
proposes to simply stop building the docs there, unless the user
provides a suitable version of Sphinx (which is easy enough with pip).
That's PATCH 7.

Paolo thinks we could also stay on 3.6 just for Sphinx, with a bit of
care.  That's constructive patch review.

All the angst about CentOS falling off the end of our "supported build
platforms" list is not actually warranted by this series :)

Some of the discussion is valuable regardless.  For instance, the points
Daniel made about traditional distro dependencies (still used with C
tool chains), and distro-agnostic dependencies baked into modern tool
chains.  This series is not (and does not try to be) the final answer to
the question how to handle Python dependencies in QEMU.