launchpad-dev team mailing list archive

[Robert Collins <robert.collins@xxxxxxxxxxxxx>]

On Wed, Sep 14, 2011 at 11:37 PM, Barry Warsaw <barry@xxxxxxxxxxxxx> wrote:
> On Sep 13, 2011, at 05:23 PM, Francis J. Lacoste wrote:
>
>>> Francis tells me that Launchpad already runs fairly well on Python 2.7 +
>>> Oneiric on developer machines, with just one or two test failures.
>>
>>That's actually from hear-say and from a while back. I don't know the exact
>>status of this today, but to me the biggest hurdles around this have always
>>been the deployment issues.
>
> Can any other LP devs confirm?

Yes. Its -always- about deployments.

Case in point: transitioning a Python version in a slow fashion in
production means:
 - buildbot (or $whatever CI) needs to run *two* version (old python
version and new one)
 - we have to do everything related to that twice for a period

If an OS upgrade is bundled into that, we have a multi-hour process
for moving each component over, so we have no choice but to go slow.

If we had a simple export PYTHON= and rebuild change, then a single
deployment can upgrade us on all machines at once. Bada-boom,
bada-bing. We do need to be reasonably sure before we kick the actual
transition off, that its going to work, but instead of a Big Deal, its
relatively no-brainer.

-Rob