Re: Locks on the Bzr repository

[Uday S Reddy <u.s.reddy@cs.bham.ac.uk>]

Richard Stallman writes:

> I can try -- but first I need a clear and self-contained description
> of the problem.  Is the problem solely one of occasional unpredictable
> failures?

Well, first of all, Bazaar itself does not have rebase.  Somebody
added a plug-in and this has been distributed with Bazaar.  My version
of Bazaar (2.1.0) came bundled with rebase 0.5.5.  The version number
below 1 doesn't inspire much confidence.  And, it has been reported
that it silently drops merges in the branch that is being rebased.  A
really serious bug, if you ask me.  I don't know what other bugs might
be lurking.  Other people that have tried it can perhaps share their
experience.  There are reports that the Bazaar team doesn't regard
rebase as a good technique at all.  So, it is unlikely that they will
provide any better support for it.

On the other hand, distributed maintenance with a clean management of
history necessarily involves rebase.  If 10 people work on bug fixes
independently, we need to be able to arrange those fixes in some
linear order when the fixes come back.  Bazaar's solution is to
provide merge, which lumps each batch of fixes together into a
subhistory without concern for any logical coherence among the
changes.  Such lumping is discouraged by Emacs development team,
understably, because, if the lumps don't have any logical coherence,
it is as if they don't exist at all.  Whoever is looking through the
history will have to look through every lump to find what he/she is
looking for.

In the absence of rebase, the Emacs developers are forced to
synchronize with the mainline for each commit they want to do.  This
wastes time.  It can also be unreliable in the long run, because
developers tend to think of the synchronization steps as being more or
less automatic rather than logical changes that they really are, which
involve review and testing.

If Bazaar is going to be the favoured VCS for all gnu projects because
of its membership in the gnu family, then it has to think about what
the rest of gnu needs.  I understand that they want to provide safe
solutions that novices can use, but they are also tying the hands of
experienced developers from using the best possible solutions.  It
would be best if they provide rebase and provide sufficient warning,
and leave it to the project managers to use them wisely.

Cheers,
Uday