dolfin team mailing list archive

[Anders Logg <logg@xxxxxxxxx>]

On Fri, Jun 17, 2011 at 11:24:21AM +0200, Marie E. Rognes wrote:
>
> On 17. juni 2011, at 11:05, "Garth N. Wells" <gnw20@xxxxxxxxx> wrote:
>
> >
> >
> > On 17/06/11 09:34, Anders Logg wrote:
> >> On Fri, Jun 17, 2011 at 08:46:46AM +0100, Garth N. Wells wrote:
> >>>
> >>>
> >>> On 17/06/11 08:35, Garth N. Wells wrote:
> >>>>
> >>>>
> >>>> On 12/06/11 21:36, Anders Logg wrote:
> >>>>> On Fri, Jun 10, 2011 at 10:33:41PM +0100, Florian Rathgeber wrote:
> >>>>> On 11/05/11 15:43, Anders Logg wrote:
> >>>>>>>> On Wed, May 11, 2011 at 03:57:52PM +0200, Anders Logg wrote:
> >>>>>>>>> On Tue, May 10, 2011 at 10:57:07PM +0200, Martin Sandve Alnæs wrote:
> >>>>>>>>>> On 10 May 2011 17:52, Anders Logg <logg@xxxxxxxxx> wrote:
> >>>>>>>>>>> On Tue, May 10, 2011 at 03:49:18PM +0200, Martin Sandve Alnæs wrote:
> >>>>>>>>>>>> On 3 May 2011 18:25, Johannes Ring <johannr@xxxxxxxxx> wrote:
> >>>>>>>>>>>>> On Tue, May 3, 2011 at 3:52 PM, Anders Logg <logg@xxxxxxxxx> wrote:
> >>>>>>>>>>>>>> It happens to me a lot. Johannes has tried to explain to me why it
> >>>>>>>>>>>>>> happens a number of times but I still don't understand why.
> >>>>>>>>>>>>>>
> >>>>>>>>>>>>>> Maybe he can try to explain it again to you and then I might also
> >>>>>>>>>>>>>> understand. :-)
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> I think I just bring up the following instructions (which I think looks good):
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> http://wiki.squid-cache.org/BzrInstructions
> >>>>>>>>>>>>
> >>>>>>>>>>>> Thanks Johannes.
> >>>>>>>>>>>>
> >>>>>>>>>>>> Basically the problem is that bazaar numbers commits with contiguous
> >>>>>>>>>>>> integers, and when Bob and Alice works locally they will get the same
> >>>>>>>>>>>> commit ids for different commits. When you stand in branch Alice and
> >>>>>>>>>>>> merge from branch Bob, the commit numbers of branch Alice are
> >>>>>>>>>>>> conserved and a single new merge commit is recorded on top there. The
> >>>>>>>>>>>> commit numbers from branch Bob are lost in the merge. Therefore, to
> >>>>>>>>>>>> conserve the commit ids in the central branch, you have to merge from
> >>>>>>>>>>>> your own branch into the server branch, not the other way around.
> >>>>>>>>>>>> Otherwise we can never safely use the commit revisions from the
> >>>>>>>>>>>> central branch, since they may change every time somebody merges the
> >>>>>>>>>>>> 'wrong way'.
> >>>>>>>>>>>>
> >>>>>>>>>>>> This problem does not occur with hg or git, because they use a hash
> >>>>>>>>>>>> value to identify a each commit.
> >>>>>>>>>>>
> >>>>>>>>>>> So if I'm Bob and Alice has pushed some changes to the main branch
> >>>>>>>>>>> before me, which exact commands should I write?
> >>>>>>>>>>
> >>>>>>>>>> Depends on how you set up your repositories, where your branches are
> >>>>>>>>>> located, etc...
> >>>>>>>>>>
> >>>>>>>>>> You really have to read up on it and try it out a bit to understand
> >>>>>>>>>> it, and I doubt I can write it better than what Johannes linked to +
> >>>>>>>>>> the bazaar docs.
> >>>>>>>>>>
> >>>>>>>>>> I plan to keep a local repository with multiple branches like this:
> >>>>>>>>>>  ~/dev/fenics/ufl/ - local ufl repository
> >>>>>>>>>
> >>>>>>>>> Is this a repository? Or is it just a directory named ufl inside which
> >>>>>>>>> you keep a number of different repositories?
> >>>>>>>>
> >>>>>>>> Talked to Martin during lunch. Here's a simple summary of what needs
> >>>>>>>> to be done to set things up correctly (Cc to dolfin-dev so everyone else
> >>>>>>>> sees this):
> >>>>>>>>
> >>>>>>>>  bzr init-repo foo
> >>>>>>>>  cd foo
> >>>>>>>>  bzr checkout lp:foo trunk
> >>>>>>>>  bzr branch trunk work
> >>>>>>>>
> >>>>>>>> We should add this to the developer page in the documentation.
> >>>>>>>>
> >>>>>>>> Everyone should adopt this and we should pick on anyone that pushes
> >>>>>>>> removed changesets.
> >>>>>
> >>>>> There's an effective way to make these pushes impossible and disable the
> >>>>> bzr "feature" of renumbering revisions: set the option
> >>>>> append_revisions_only=True in <yourbranch>/.bzr/branch/branch.conf
> >>>>>
> >>>>> For branches on launchpad this works as follows:
> >>>>> 1) sftp bazaar.launchpad.net
> >>>>>     cd ~user/project/branch/.bzr/branch
> >>>>>     get branch.conf
> >>>>> 2) edit the downloaded file, adding append_revisions_only = True
> >>>>> 3)   put branch.conf
> >>>>>
> >>>>> I suggest doing this for all branches on launchpad to enforce consistent
> >>>>> revision numbers.
> >>>>>
> >>>>> More background: http://stackoverflow.com/questions/5413602
> >>>>>
> >>>>>> Thanks. I've fixed this now for DOLFIN, FFC, UFL, UFC, FIAT.
> >>>>>
> >>>>
> >>>> Could you please undo this. I can't push changes from my personal branch
> >>>> to DOLFIN. I don't see that this change has any use. (If we want cvs,
> >>>> then we should use cvs.)
> >>>>
> >>>> I've tried to follow the instructions to undo the change, but can't get
> >>>> it to work.
> >>>>
> >>>
> >>> I've undone this for DOLFIN so I could push my changes.
> >>
> >> You should have figured out how to do the merge properly instead. We
> >> should add it back to force everyone to learn how to use bzr. ;-)
> >>
> >
> > Merge is 'bzr merge xxx'. That's a proper merge.
> >
> >> The point is to not rewrite history for the common repo. This is not
> >> the same as cvs. It's still distributed but it means merges have to be
> >> done more carefully.
> >>
> >
> > There is no history re-writing. It's just adding changesets. Unique
> > changeset numbering that bzr does will always be problematic with
> > distributed version control. If you want a unique identifier, use the
> > revision id.
> >
> >> Just do this next time and it should work:
> >>
> >> 1. Make sure you have a local bound dolfin branch:
> >>
> >>  bzr checkout lp:dolfin trunk
> >>
> >> 2. Merge *from* that branch, not push to it:
> >>
> >>  cd trunk
> >>  bzr merge <path to your local repo>
> >>  bzr commit -m merge
> >>
> >
> > It just worked before. It was simpler, and I could work against any
> > branch, like by personal branch under dolfin-core.
> >
>
> After trying the no-revisions-removed approach for a while, I also find it significantly more cumbersome, especially with the main vs personal branches.
>
> Although I see the point, I never encountered a problem with the changing revision numbers before.

If Garth can't be bothered, maybe you could describe a specific
example that doesn't work?

--
Anders