[python-committers] Revert changes which break too many buildbots

[Nick Coghlan]

On 15 June 2017 at 23:38, Victor Stinner <victor.stinner at gmail.com> wrote:
> 2017-06-15 5:31 GMT+02:00 Nick Coghlan <ncoghlan at gmail.com>:
>> For example, something that would be genuinely helpful would be a bot
>> monitoring PR comments that could automate the "custom-build" dance
>> for core developers (i.e. we'd be able to write something like
>> "BuildBot: test custom build", and it would go away, kick off a custom
>> BuildBot run by pushing the PR to the "custom-build" branch, and then
>> report back the links for failed builds like
>> http://buildbot.python.org/all/builders/x86%20Tiger%20custom/builds/5
>> )
>
> I don't think that buildbots have enough resources to run tests on
> each PR. We get too many PR and each PR is updated regulary. On some
> buildbots, a single build can take 1 hour (or longer)...

I wasn't proposing running every PR through BuildBot, I was suggesting
having a more straightforward way of triggering custom builds directly
from the PR we want to test after post-merge CI has indicated it's
necessary.

However, I think there's a way of handling that which doesn't require
any new automation code to be written. Instead, we can have the policy
be to post a link to
https://docs.python.org/devguide/buildbots.html#custom-builders on the
PR that is being reverted.

That way, even if folks didn't notice the problem with the buildbots themselves:

1. They get a ping on a PR that they're necessarily following
2. They get a reminder of how to test the revised PR across the
buildbot fleet prior to merging it again

Hopefully reversions will continue to be rare (since relatively few
changes are likely to be as platform dependent as PEP 538, and
Windows/*nix differences are already covered in pre-merge CI), but
when they do come up, the reminder of how to manually trigger
pre-merge cross-platform CI is likely to be useful, and doesn't
require much additional effort on the part of the folks doing the
reversion.

Cheers,
Nick.

-- 
Nick Coghlan   |   ncoghlan at gmail.com   |   Brisbane, Australia