git-svn changing file:// to svn+ssh://

I'm working on preparing Git SVN mirrors.

I had tested my procedure on a small project and it was working fine.

On a large project it is failing. Here is what I have done:

I have cloned the repository using:

    $ git svn clone --prefix=svn/ file:///path/repo \
	--revision=15314:HEAD --trunk=trunk/project \
	--tags=tags/project --branches=branches/project \
	--branches="branches/global/*/project" project

Not simple, ok but working :)

Now I have converted the file:// to svn+ssh:// using:

    $ git gc

    $ git filter-branch --msg-filter \
     'sed "s,git-svn-id: file:///path/repo,git-svn-id: 
svn+ssh://server/repo,g"' \
     $(cat .git/packed-refs | awk '// {print $2}' | grep -v 'pack-refs')

    $ rm -fr .git/svn

I have edited .git/config to change the url string too.

Up to there, no problem. But when trying to rebase and reconstruct all rev_map files with:

    $ git svn rebase

I get the following lines again and again:

Rebuilding .git/svn/svn/trunk/.rev_map.f8352e7e-cb20-0410-8ce7-b5d9e71c585c ... Done rebuilding .git/svn/svn/trunk/.rev_map.f8352e7e-cb20-0410-8ce7-b5d9e71c585c Rebuilding .git/svn/svn/trunk/.rev_map.f8352e7e-cb20-0410-8ce7-b5d9e71c585c ... Done rebuilding .git/svn/svn/trunk/.rev_map.f8352e7e-cb20-0410-8ce7-b5d9e71c585c

...

The file .git/svn/svn/trunk/.rev_map.f8352e7e-cb20-0410-8ce7-b5d9e71c585c is in fact not created.

What could be wrong?

How should I proceed to debug this?

Any help appreciated.

Last note I've tried all this with Git 1.6.4 and 1.6.5.

Thanks, Pascal.