Re: Python 3.5 EOL; when can require 3.6?

[Peter Maydell]

On Wed, 16 Sep 2020 at 08:43, Markus Armbruster <armbru@redhat.com> wrote:
> We require Python 3.5.  It will reach its "end of life" at the end of
> September 2020[*].  Any reason not to require 3.6 for 5.2?  qemu-iotests
> already does for its Python parts.

I think these things really ought to start with the converse question:
what is the important new thing that 3.6 brings to the table that
makes it worth moving our minimum requirement forward ?
If our code still works on 3.5 and there's nothing we really want to
do to the code that would be awkward to do without insisting on
3.6, why should we irritate users by arbitrarily bumping the version
requirement ?

Also as Dan notes upstream's EOL policies aren't very relevant,
because our policy is based on what distros ship.

My broader point of view: C does not have any kind of infrastructure
like Rust's cargo or node's npm that makes it easy for a project to
say "we depend on these versions of these other packages" and
have them be satisified in a fairly painless-to-the-end-user/distro
way. So I prefer to take the approach of being as conservative as
possible about what we depend on, because the alternative tends
to be either pain for the person trying to compile QEMU (when they
have to scrabble around finding and building dependencies they
don't have conveniently to hand) or pain for us (when we have
to ship a dependency as a submodule). The default should be
"leave the version dependency where it is", not "bump the version
dependency as soon as we can".

thanks
-- PMM