[core-workflow] We will be moving to GitHub

[Ezio Melotti]

Hi,

On Fri, Jan 1, 2016 at 9:21 PM, Brett Cannon <brett at python.org> wrote:
> I don't think this will be a shock to anyone who has followed the discussion
> on this list. The decision is essentially based on:
>
> No major distinguishing features between GitHub or GitLab
> Familiarity amongst core devs -- and external contributors -- with GitHub
> Guido prefers GitHub
>
> Neither platform had some mind-blowing feature(s) that really made them
> stand out from each other such that it would greatly simplify our lives if
> we chose one platform over another. I obviously was really hoping there was
> going to be something I missed, but nothing ever came up (and no, being open
> source is not enough of a feature; as I said when I started this process,
> being open source would help break ties or minor lead of one tool but not be
> a deciding factor).
>
> But what Github does have over GitLab is familiarity. While there were
> people who publicly said they would prefer not to go with GitHub but would
> begrudgingly use it if we chose to go that route, I had multiple core devs
> email me privately saying they hoped I would choose GitHub. I think most of
> that stemmed from having used GitHub for other open source projects and/or
> work, making even dormant core devs say they would be able to become active
> again if we switched to GitHub thanks to eliminating the barrier of having
> to keep up with our custom workflow for code reviews and using hg for
> commits. And while I said it wasn't a goal to make things easier for
> external contributors, I also can't ignore the fact that the vast majority
> of people out there who might want to help out are already familiar with
> GitHub.
>
> And at least for me, the fact Guido prefers GitHub means something. While
> Guido himself would say I shouldn't really worry about his preferences since
> he is only an occasional contributor at this point, I believe that it's
> important that our BDFL actually like contributing to his own programming
> language rather than potentially alienating him because he finds the process
> burdensome.
>
> So that's why I have chosen GitHub over GitLab. Please realize that this is
> choosing GitHub to provide repository hosting and code review; we are not
> moving our issue tracker, nor are we moving our wiki. And the long-term plan
> is to set up a bot that will handle our commit workflow which will help
> isolate us from any repository hosting platform we are on and making moving
> easier in the future (and short-term people will use the command-line and
> that's totally platform-agnostic).
>
> Thanks to everyone who contributed to this decision, especially Donald,
> Barry, and Nick for making the proposals we had to work from.
>
> We can start the discussion of how we want to handle the transition next
> week, but I'm going to try and step away from this whole workflow topic
> until Monday so I can spend the last couple of days of my vacation not
> thinking about this stuff. :)
>

This will likely require a new PEP, that should cover:
  1) the new workflow (including how to handle reviews -- see below);
  2) the steps required for the migration and a timeline;
  3) a list of things that will break and/or that will need to be
added/replaced before/during/after the migration;
  4) the fate of hg.python.org;

Some of these things might already be covered by existing PEPs, but I
don't see them in PEP 507[0] and 481[1] (and I'm getting a bit lost
among all the competing PEPs and multiple threads across at least a
couple different MLs :).

Above you said that GitHub will be used for reviews but we will keep
using our bug tracker.
This leads to the following questions:
  * Do GitHub reviews only work for pull requests?
  * Are we still going to support uploading diffs/patches to the
tracker (short term and long term)?
  * If so, how/where are we going to review those diffs/patches?
  * Will patches be automatically converted to pull requests, or pull
requests converted to patches and attached to b.p.o issues?
  * Are there plans to migrate existing Rietveld reviews to GitHub and
shut Rietveld down for good?
  * If not, will Rietveld stay around and be read-only?  Or will it
still be used for patches uploaded to b.p.o?
  * What else is needed to integrate GitHub and b.p.o?

About points 3 of the initial list, these are some examples of things
that will need to be added/updated/replaced:
  * the hgroundup hook[2] that post messages to b.p.o when a commit
includes an issue number needs to be replaced;
  * the hgirker hook[3] used for deadparrot on #python-dev needs to be
replaced (probably there is already an irker-git hook that can be
used/adapted);
  * the hgbuildbot[4] hook that triggers the buildbots on commit needs
to be replaced;
  * other hg hooks[5] might need to be rewritten/replaced;
  * the script[6] that generates bug tracker links to hg.p.o needs to
be updated (for both cs ids and paths);
  * the hg code that converts issue links in commit messages to b.p.o
links needs to be replaced;
  * other places where issue numbers appears on GitHub should generate
links to b.p.o;
  * the hg-cpydev hg extension [7] should be ported to git (optional);
  * the buildbots need to be updated if they are going to pull the
source from github and use git;
  * the bug tracker will need to be updated to interact with github;
  * the devguide needs to be updated (both to cover the new workflow
and update links/commands);

FWIW next weekend (9-10 January) we are organizing a sprint in
Helsinki, and I'm planning to work on the bug tracker, so I might be
able to start addressing some of these points.

Best Regards,
Ezio Melotti

P.S. enjoy your last few days of vacation while you can ;)

[0]: https://www.python.org/dev/peps/pep-0507/
[1]: https://www.python.org/dev/peps/pep-0481/
[2]: https://hg.python.org/hooks/file/tip/hgroundup.py
[3]: https://hg.python.org/hooks/file/tip/hgirker.py
[4]: https://hg.python.org/hooks/file/tip/hgbuildbot.py
[5]: https://hg.python.org/hooks/file/tip
[6]: https://hg.python.org/tracker/python-dev/file/tip/extensions/local_replace.py
[7]: https://bitbucket.org/introom/hg-cpydev