dolfin team mailing list archive

["Garth N. Wells" <gnw20@xxxxxxxxx>]

On 17/06/11 10:28, Anders Logg wrote:
> 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?
>

Why would I bother with something that I think is pointless and
cumbersome? Like Marie, I have never had a problem with the present
approach.

Garth

> --
> Anders