Possibly Dumb Question about Switching a Bazaar Branch from Subversion to Git

[Jelmer Vernooij]

Hi Russel,

On 03/08/10 14:11, Russel Winder wrote:
> I have got myself in a bit of a tiz about my Gant branches, but it is
> probably because I am missing something simple.
>
> I have a shared repository containing all the maintenance branches of
> Gant plus a trunk.  All of these used to be branches bound to a
> Subversion repository.  The Subversion repository has now disappeared to
> be replaced by a Git repository.  I unbound all the branches and would
> now like to rebind to the Git repository.  Clearly for the moment I
> cannot do anything about the maintenance branches, but I should be able
> to do something about the master/trunk branch.
>
> I naïvely tried:
>
> 	bzr merge --preview<URL>
>
> but it says:
>
>          bzr: ERROR: Branches have no common ancestor, and no merge base revision was specified.
>
> which is both true and false.  I know the actual content is identical
> but the common ancestor of the Git repository and the Bazaar branch is
> the Subversion repository -- the Git repository I am trying to bind to
> is a mirror of a repository I created from the Subversion repository by
> "git svn-clone --stdlayout . . ."
>
> As a last resort I can just retire the Bazaar shared repository and
> create things anew from the Git repository.  So there is no panic --
> except that I will have to overwrite the public branches on Launchpad
> which could be seen as impolite (!)  However I have this luxury only
> because the branch/repository is small with only a few thousand
> revisions.
>
> Am I just missing something or is this a dark corner where there be
> dragons?
>
>    
There is no common history here, so there isn't much that can be done. 
You could do a "bzr merge -r0..-1" to force a merge but you would get a 
lot of file conflicts because the files have no common ancestry.

I'd recommend just switching over to the new branch and asking people to 
"bzr pull --overwrite" from the public branches to get the new git-based 
Bazaar branch.

Cheers,

Jelmer