[Numpy-discussion] Moving away from svn ?

[David Cournapeau]

On Jan 5, 2008 4:38 PM, Robert Kern <robert.kern at gmail.com> wrote:
> Chris Barker wrote:
> > hmmm. Everyone posting so far seems to be positive on this idea, but I'm
> > not so sure. A few thoughts:
> >
> > 1) change is bad. It may be worth it, but this decision needs to be made
> > very differently than if we were starting from scratch.
> >
> > 2) apparently svn merge sucks compared  to other merge technology. svn
> > (and cvs before it) is the only system I'm used, and yes, merging is
> > painful, but I have to say that it appeared to be painful because it's a
> > very hard problem. Can anyone comment on why these other systems seem so
> > much better? Does it have anything to do with Centralized vs.
> > Distributed at all?
>
> Tangentially, yes. DVCSes need to keep track of more information in order to be
> distributed. That information is extremely useful for managing merges properly.
> Centralized systems could track this information, but they don't *need* to in
> order to be functional, so they mostly haven't, yet.
>
> For each revision, the DVCS knows what revisions it derives from. SVN does not
> keep this information. SVN primarily just knows the text diffs from revision to
> revision. In particular, if I have a long-lived branch, I am going to merge in
> changes from the trunk while I'm working on it. When I go to merge the branch
> back into the trunk, I need to know which trunk-revisions I've already merged
> into the branch. SVN does not track this information. Tools like svnmerge.py
> track some of this information at the expense of some added clumsiness.
>
> It's worth noting that SVN 1.5 will be tracking such information. But that
> release is a long ways off.
>
My understanding, but I do not follow svn much, is that in 1.5, you
will only get what svnmerge gives you today.

David