import git (once svn) repository from googlecode

I want to import a git repository from Google Code. But it fails with http://launchpadlibrarian.net/82551568/chimaira-development-chimaira-packages.log :

2011-10-11 16:25:12 INFO Starting job.
2011-10-11 16:25:12 INFO Getting exising bzr branch from central store.
2011-10-11 16:25:13 INFO [chan bzr SocketAsChannelAdapter] Opened sftp connection (server version 3)
2011-10-11 16:25:13 INFO 35 bytes transferred
2011-10-11 16:25:13 INFO [chan bzr SocketAsChannelAdapter] Opened sftp connection (server version 3)
2011-10-11 16:25:14 INFO Importing branch.
2011-10-11 16:25:21 INFO finding revisions to fetch 0
2011-10-11 16:25:22 INFO finding revisions to fetch:generating index 0/1918
2011-10-11 16:25:23 INFO finding revisions to fetch 1
2011-10-11 16:25:23 INFO
Traceback (most recent call last):
  File "/srv/importd.launchpad.net/production/launchpad-rev-14124/scripts/code-import-worker.py", line 98, in <module>
    sys.exit(script.main())
  File "/srv/importd.launchpad.net/production/launchpad-rev-14124/scripts/code-import-worker.py", line 93, in main
    return import_worker.run()
  File "/srv/importd.launchpad.net/production/launchpad-rev-14124/lib/lp/codehosting/codeimport/worker.py", line 550, in run
    return self._doImport()
  File "/srv/importd.launchpad.net/production/launchpad-rev-14124/lib/lp/codehosting/codeimport/worker.py", line 740, in _doImport
    inter_branch.fetch(limit=revision_limit)
  File "/srv/importd.launchpad.net/production/launchpad-rev-14124/bzrplugins/optional/git/branch.py", line 666, in fetch
    self.fetch_objects(stop_revision, fetch_tags=fetch_tags, limit=limit)
  File "/srv/importd.launchpad.net/production/launchpad-rev-14124/bzrplugins/optional/git/branch.py", line 689, in fetch_objects
    determine_wants, self.source.mapping, limit=limit)
  File "/srv/importd.launchpad.net/production/launchpad-rev-14124/bzrplugins/optional/git/fetch.py", line 676, in fetch_objects
    limit)
  File "/srv/importd.launchpad.net/production/launchpad-rev-14124/bzrplugins/optional/git/fetch.py", line 491, in import_git_objects
    target_git_object_retriever, trees_cache)
  File "/srv/importd.launchpad.net/production/launchpad-rev-14124/bzrplugins/optional/git/fetch.py", line 370, in import_git_commit
    parent_trees = trees_cache.revision_trees(rev.parent_ids)
  File "/srv/importd.launchpad.net/production/launchpad-rev-14124/bzrplugins/optional/git/object_store.py", line 112, in revision_trees
    return list(self.iter_revision_trees(revids))
  File "/srv/importd.launchpad.net/production/launchpad-rev-14124/bzrplugins/optional/git/object_store.py", line 106, in iter_revision_trees
    for tree in self.repository.revision_trees(todo):
  File "/srv/importd.launchpad.net/production/launchpad-rev-14124/eggs/bzr-2.5.0dev2_r6152-py2.6-linux-x86_64.egg/bzrlib/vf_repository.py", line 1794, in revision_trees
    for inv in inventories:
  File "/srv/importd.launchpad.net/production/launchpad-rev-14124/eggs/bzr-2.5.0dev2_r6152-py2.6-linux-x86_64.egg/bzrlib/repofmt/groupcompress_repo.py", line 981, in _iter_inventories
    raise errors.NoSuchRevision(self, record.key)
bzrlib.errors.NoSuchRevision: CHKInventoryRepository('file:///srv/importd.launchpad.net/data/worker-for-branch-517295/bzr_branch/.bzr/repository/') has no revision ('git-v1:a416d1fb4662544f6bac0bbc528b5dc8d1f39f87',)
Import failed:
Traceback (most recent call last):
Failure: twisted.internet.error.ProcessTerminated: A process has ended with a probable error condition: process ended with exit code 1.

See also https://code.launchpad.net/~chimaira-development/chimaira/packages for branch site. Actually launchpad fetches from "https://code.google.com/p/chimaira.git" but "https://code.google.com/p/chimaira" results same error.

Perhaps it is important that this git repo was a svn repo originally.

How can I prevent this error and achieve an successful import? Thanks in advance.