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On 11/26/2012 11:40 AM, Monty Taylor wrote:
> Hey all!
>
> I started a discussion during a TC meeting a little while ago that needs
> more general input and feedback. The question at hand is "what versions
> of python and what versions of what distros do we care about as a project?"
>
> First of all, this isn't a discussion about what CI will test or what
> we'll use for gating.  It's more of a conversation about what language
> and OS assumptions developers can make when they are writing code, so
> that design and review choices can be made.
>
> To put it more bluntly, if someone files a bug or a code review comment
> that says:
>
> "Blah doesn't work in python X"
>
> When can we respond "not a bug/won't fix" with a clear conscience?
>
> When we first started the project, we said out loud that development was
> always focused on the current release of Ubuntu and that's it. We picked
> that because doing _development_ targeting a bazillion distro options at
> the same time gets hairy quickly, and I think the clarity served has us
> well. But I'm pretty sure things have changed since then - latest Ubuntu
> does not come with python 2.6, for instance, but we still seem to care
> about it.
>
> With that background, I'd like to start things off by proposing the
> following:
>
> a) We continue to focus development efforts of master on the latest
> release of Ubuntu with python libraries coming from PyPI.
> b) We don't introduce things into master that would be unworkable on
> either latest Ubuntu LTS or latest RHEL.
>
> Logistically, because of our development focus on pypi modules in
> virtualenvs, this doesn't affect much for developers outside of base
> python versions and a few things that can't go in a virtualenv like
> libvirt or the kernel. Since RedHat and Canonical have both committed to
> maintaining special backport repos for those things for users of RHEL
> and Ubuntu LTS, I don't think in practice it's going to have much of a
> noticeable impact.
>
> Except where it comes to base python versions.
>
> If we take the above to be correct, it has the following effect:
>
> - We need to care about python 2.6 compatibility until such a time as
> there is a RHEL that has 2.7 in it.

+1

> - 2.7 should be our current dev focus, so if possible we should code to
> 2.7 libs and then use backport packages like unittest2 to make 2.6 happy.

I know one of the ways I had a change get caught was on trying to use an 
assert that wasn't available in 2.6 in one of the tests. Will the 
backport solve that problem?

> - We can't REALLY start thinking about Python3 in earnest until a RHEL
> release comes out with python 2.7, because 2.7/3.3 are needed for
> source-code compatible code

+1

> Net result - pretty much exactly what we're doing today, it just gets it
> down on paper a little better.
>
> Thoughts? Disagreements?

I think support of last RHEL and Ubuntu LTS is a very good stake in the 
ground, and I'm completely happy with that. We can let the folks from 
those various groups let us know when it would be sane to roll forward.

	-Sean

-- 
Sean Dague
IBM Linux Technology Center
email: sdague at linux.vnet.ibm.com
alt-email: sldague at us.ibm.com