dolfin team mailing list archive

[Anders Logg <logg@xxxxxxxxx>]

On Fri, Jun 17, 2011 at 10:05:04AM +0100, Garth N. Wells 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.

I agree it was simpler before, but believe one can still accomplish
the same type of workflow (just with different commands).

Can you sketch a specific example that I can try?

--
Anders