Re: How to use git-svn to clone from a mirror?

From: David Kastrup <dak@gnu.org>
Date: Jun 5, 2007, 06:41 UTC
Message-ID: <86r6oqoqdd.fsf@lola.quinscape.zz>
In-Reply-To: <Pine.LNX.4.64.0706041906570.4046@racer.site>

Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:

Show 38 quoted lines

> On Mon, 4 Jun 2007, Raja R Harinath wrote:
>
>> David Kastrup <dak@gnu.org> writes:
>> 
>> > I have used something like
>> >
>> > git-svn clone -T trunk -b branches -t tags file:///tmp/rsync-mirror
>> >
>> > to clone an rsync mirror of an SVN repository.  Now I want to have 
>> > fetch revert to pulling from the upstream repository in future. 
>> > However, if I change the respective line in .git/config to 
>> > svn://the.svn.link/whatever, git-rebase will fetch the right updates, 
>> > but then says that it can't work with the objects in the git 
>> > repository.
>> >
>> > Changing the config back will make git-rebase -l work.
>> >
>> > So what would be the right procedure to shift the SVN source from an
>> > rsync mirror to the original, without git-svn breaking?
>> 
>> I think you'll have to
>> 
>> -------------8<------------
>>   # remove stored revision db, since we're going to change all the commit ids
>>   rm .git/svn/git-svn/.rev_db.*
>> 
>>   # rewrite git-svn-id: lines
>>   cg-admin-rewritehist \
>> 	--msg-filter \
>> 	'sed "s,file:///tmp/rsync-mirror,svn://the.svn.link/whatever,"'
>> 
>>   # recreate new revision db, and fetch updates, if any
>>   git-svn rebase
>> -------------8<------------
>
> <shameless plug>
> 	Or you use the just-rewritten version of it, git-filter-branch.
> </shameless>

Well, part of the reason I worked from an rsynced copy was to be able to repeat the experiment by just wasting a few hours of time each time, without wasting more bandwidth.

What I arrived at was to use
git-svn init -T trunk -t tags -b branches
  --rewrite-root svn://tug.org/texlive file:///mirror/texlive
git-svn fetch --all
[edit .git/config and replace the url and rewrite-root lines with a
 single url line pointing to the root]
git-reset --hard   [don't ask me why]
and afterwards fetches worked online.

I liked the commit messages when using --no-metadata better than with --rewrite-root, but I found no way to get the resulting archive operative for git-svn rebase afterwards.

Could someone explain to me why git needs to know the upstream URL history, whether by --rewrite-root or rewrite-hist or git-filter-branch?

I find this rather hard to understand, so I would like to get an idea where this fits naturally into the overall design of git, and how it makes sense.

Thanks,

-- 
David Kastrup