bzr-git 0.4.1 crashes when branching parted git tree

[Robert Millan]

$ bzr branch git://git.debian.org/git/parted/parted.git
bzr: ERROR: exceptions.NotImplementedError: <function import_git_submodule at 0x1b7dc08>

Traceback (most recent call last):
  File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 842, in exception_to_return_code
    return the_callable(*args, **kwargs)
  File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 1037, in run_bzr
    ret = run(*run_argv)
  File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 654, in run_argv_aliases
    return self.run(**all_cmd_args)
  File "/usr/lib/python2.5/site-packages/bzrlib/builtins.py", line 1243, in run
    source_branch=br_from)
  File "/usr/lib/python2.5/site-packages/bzrlib/bzrdir.py", line 1185, in sprout
    result_repo.fetch(source_repository, fetch_spec=fetch_spec)
  File "/usr/lib/python2.5/site-packages/bzrlib/repository.py", line 1695, in fetch
    find_ghosts=find_ghosts, fetch_spec=fetch_spec)
  File "/usr/lib/python2.5/site-packages/bzrlib/plugins/git/fetch.py", line 377, in fetch
    mapping=mapping, fetch_spec=fetch_spec)
  File "/usr/lib/python2.5/site-packages/bzrlib/plugins/git/fetch.py", line 402, in fetch_refs
    pack_hint = self.fetch_objects(determine_wants, mapping, pb)
  File "/usr/lib/python2.5/site-packages/bzrlib/plugins/git/fetch.py", line 462, in fetch_objects
    store, recorded_wants, pb)
  File "/usr/lib/python2.5/site-packages/bzrlib/plugins/git/fetch.py", line 334, in import_git_objects
    parent_invs, target_git_object_retriever._idmap, lookup_object)
  File "/usr/lib/python2.5/site-packages/bzrlib/plugins/git/fetch.py", line 240, in import_git_tree
    file_id, revision_id, parent_invs, shagitmap, lookup_object)
  File "/usr/lib/python2.5/site-packages/bzrlib/plugins/git/fetch.py", line 167, in import_git_submodule
    raise NotImplementedError(import_git_submodule)
NotImplementedError: <function import_git_submodule at 0x1b7dc08>

bzr 2.0.1 on python 2.5.4 (Linux-2.6.26-libre2-2-amd64-x86_64-with-debian-squeeze-sid)
arguments: ['/usr/bin/bzr', 'branch', 'git://git.debian.org/git/parted/parted.git']
encoding: 'UTF-8', fsenc: 'UTF-8', lang: 'ca_AD.UTF-8'
plugins:
  bzrtools /usr/lib/python2.5/site-packages/bzrlib/plugins/bzrtools [2.0.1]
  cia /usr/lib/python2.5/site-packages/bzrlib/plugins/cia [1.0.0dev]
  cvsps_import /usr/lib/python2.5/site-packages/bzrlib/plugins/cvsps_import [unknown]
  fastimport /home/rmh/.bazaar/plugins/fastimport [0.9.0dev]
  git /usr/lib/python2.5/site-packages/bzrlib/plugins/git [0.4.1]
  launchpad /usr/lib/python2.5/site-packages/bzrlib/plugins/launchpad [2.0.1]
  netrc_credential_store /usr/lib/python2.5/site-packages/bzrlib/plugins/netrc_credential_store [2.0.1]
  rebase /usr/lib/python2.5/site-packages/bzrlib/plugins/rebase [0.5.4]
  svn /usr/lib/python2.5/site-packages/bzrlib/plugins/svn [1.0.0]

*** Bazaar has encountered an internal error. This probably indicates a
    bug in Bazaar. You can help us fix it by filing a bug report at
        https://bugs.launchpad.net/bzr/+filebug
    including this traceback and a description of the problem.