[Python-Dev] PEP 481 - Migrate Some Supporting Repositories to Git and Github

[Alex Gaynor]

Donald Stufft <donald <at> stufft.io> writes:

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I strongly support this PEP. I'd like to share two pieces of information. Both
of these are personal anecdotes:

For the past several years, I've been a contributor on two major projects using
mercurial, CPython and PyPy. PyPy has a strong culture of in-repo branching,
basically all contributors regularly make branches in the main repo for their
work, and we're very free in giving people commit rights, so almost everyone
working on PyPy in any way has this level of access. This workflow works ok. I
don't love it as much as git, but it's fine, it's not an impediment to my work.

By contrast, CPython does not have this type of workflow, there are almost no
in-tree branches besides the 2.7, 3.4, etc. ones. Despite being a regular hg
user for years, I have no idea how to create a local-only branch, or a branch
which is pushed to a remote (to use the git term). I also don't generally
commit my own work to CPython, even though I have push privledges, 
because I
prefer to *always* get code review on my work. As a result, I use a git mirror
of CPython to do all my work, and generate patches from that.

The conclusion I draw from this is that hg's workflow is probably fine if
you're a committer on the project, or don't ever need to maintain multiple
patches concurrently (and thus can just leave everything uncommitted in the
repo). However, the hg workflow seems extremely defficient at non-committer
contributors.

The seconds experience I have is that of Django's migration to git and github.
For a long time we were on SVN, and we were very resistant to moving to 
DVCS in
general, and github in particular. Multiple times I said that I didn't see how
exporting a patch and uploading it to trac was more difficult than sending a
pull request. That was very wrong on my part.

My primary observation is not about new contributors though, it's actually
about the behavior of core developers. Before we were on github, it was fairly
rare for core developers to ask for reviews for anything besides *gigantic*
patches, we'd mostly just commit stuff to trunk. Since the switch to github,
I've seen that core developers are *far* more likely to ask for reviews of
their work before merging.

Big +1 from me, thanks for writing this up Donald,
Alex