[Python-Dev] Mercurial migration: help needed

[Stephen J. Turnbull]

Antoine Pitrou writes:

 > > In addition, a DVCS brings in another problem dimension: when people
 > > push their changes, they have *already* committed them - and perhaps not
 > > even they, but a contributor from which they had been pulling changes.
 > > The bogus change may have been weeks ago, so the subversion solution
 > > (of rejecting the commit to happen) doesn't quite work that well for
 > > a DVCS.

git has a nice filter-branch command, which would allow you to
automatically repair the problem (it works basically by checking out
each changeset and rerecording it with the appropriate commands).  I
know bzr is growing something similar, so presumably it is or will
soon be available in hg.

 > I don't think this problem is really serious.
 > If the push fails, you can just commit (locally) a new changeset that
 > repairs the EOL or indentation problems, and push the whole bunch of
 > changesets again (I assume the server-side hook will not examine
 > changesets individually, but only the last of them?).

That's not a very good solution.  Especially with typical Mercurial
workflows[1], it's quite possible that you'll have a number of bogus
changesets interleaved with good one.  I don't think recording a
repair is satisfactory.

Footnotes: 
[1]  Note that DVCS means you do *not* have to follow Python workflows
in your private branches.