On Wed, Feb 22, 2023 at 03:37:51PM +0100, Paolo Bonzini wrote:
Python 3.6 was EOL 2021-12-31. Newer versions of upstream libraries have
begun dropping support for this version and it is becoming more
cumbersome to support. Avocado-framework and qemu.qmp each have their
own reasons for wanting to drop Python 3.6, but won't until QEMU does.
Versions of Python available in our supported build platforms as of today,
with optional versions available in parentheses:
openSUSE Leap 15.4: 3.6.15 (3.9.10, 3.10.2)
CentOS Stream 8: 3.6.8 (3.8.13, 3.9.16)
CentOS Stream 9: 3.9.13
Fedora 36: 3.10
Fedora 37: 3.11
Debian 11: 3.9.2
Alpine 3.14, 3.15: 3.9.16
Alpine 3.16, 3.17: 3.10.10
Ubuntu 20.04 LTS: 3.8.10
Ubuntu 22.04 LTS: 3.10.4
NetBSD 9.3: 3.9.13*
FreeBSD 12.4: 3.9.16
FreeBSD 13.1: 3.9.16
OpenBSD 7.2: 3.9.16
Note: Our VM tests install 3.7 specifically for freebsd and netbsd; the
default for "python" or "python3" in FreeBSD is 3.9.16. NetBSD does not
appear to have a default meta-package, but offers several options, the
lowest of which is 3.7.15. "python39" appears to be a pre-requisite to
one of the other packages we request in tests/vm/netbsd.
Since it is safe to under our supported platform policy, bump our
minimum supported version of Python to 3.7.
In the above list of versions, there's no platform which actually
has 3.7 as a limiting factor. THe only mention of 3.7 comes from
our own VM scripts, which for freebsd is outdated compared to
their default, and for netbsd the 3.7 choice appears arbitrary
on our side given their lack of default.
Ubuntu 20.04 on 3.8 would be the hard constraint out of the above
list of distros.
Our normal practice wrt the support policy would be to go to the
baseline from the above distro list. IOW, if we're dropping 3.6,
then going to 3.8 would be the normal course of action, rather
than stopping at 3.7 which doesn't appear needed by our targetted
distros.