Re: [Qemu-devel] Deprecation policy and build dependencies

[Daniel P . Berrangé]

On Mon, Jun 03, 2019 at 02:26:49PM +0200, Markus Armbruster wrote:
> John Snow <address@hidden> writes:
> 
> > On 5/31/19 3:24 PM, Eduardo Habkost wrote:
> >> Long story short: I would really like to drop support for Python
> >> 2 in QEMU 4.1.
> 
> The sooner, the better, as far as I'm concerned.
> 
> >> What exactly prevents us from doing this?  Does our deprecation
> >> policy really apply to build dependencies?
> >> 
> >
> > Normally I'd say it's only nice to also follow the depreciation policy
> > for tooling as well to give people a chance to switch away, but with
> > regards to Python2, I feel like we're in the clear to drop it for the
> > first release that will happen after the Python2 doomsday clock.
> >
> > (So, probably 4.2.)
> 
> In addition to our feature deprecation policity, we have a "Supported
> build platforms" policy (commit 45b47130f4b).  The most common holdback
> is this one:
> 
>     For distributions with long-lifetime releases, the project will aim
>     to support the most recent major version at all times. Support for
>     the previous major version will be dropped 2 years after the new
>     major version is released. For the purposes of identifying supported
>     software versions, the project will look at RHEL, Debian, Ubuntu
>     LTS, and SLES distros. Other long-lifetime distros will be assumed
>     to ship similar software versions.
> 
> RHEL-7 has Python 3 only in EPEL.  RHEL-8 came out last month.  Unless
> we interpret our policy to include EPEL, this means supporting Python 2
> for some 16 months after upstream Python retires it.  My personal
> opinion: nuts.

We've not said whether this refers to only base repos, or whether addon
repos are accepted. IMHO, we are reasonably justified in saying RHEL-7
as a build platform covers any repo provided by Red Hat, which would
give us Python3 via software collections. I think it would be reasonable
to also state it covers EPEL, since EPEL is such a commonly used repo
with RHEL.

IOW, I don't think RHEL-7 support as a build platform blocks us from
dropping py2. We merely need to tweak our build platforms doc to clarify
our intent wrt add-on yum repos.

Regards,
Daniel
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