Branch of an empty repo bombs out

Trying to branch an empty git repo from github dies horribly:

mathrick@megumi /tmp $ bzr branch git://<email address hidden>/mathrick/FreshEmptyRepo.git
bzr: ERROR: exceptions.TypeError: 'NoneType' object is not iterable

Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 930, in exception_to_return_code
    return the_callable(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 1121, in run_bzr
    ret = run(*run_argv)
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 673, in run_argv_aliases
    return self.run(**all_cmd_args)
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 697, in run
    return self._operation.run_simple(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/cleanup.py", line 136, in run_simple
    self.cleanups, self.func, *args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/cleanup.py", line 166, in _do_with_cleanups
    result = func(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/builtins.py", line 1468, in run
    revision_id = br_from.last_revision()
  File "/usr/lib/python2.7/dist-packages/bzrlib/plugins/git/remote.py", line 498, in last_revision
    return self.lookup_foreign_revision_id(self.head)
  File "/usr/lib/python2.7/dist-packages/bzrlib/plugins/git/remote.py", line 504, in head
    refs = self.bzrdir.get_refs_container()
  File "/usr/lib/python2.7/dist-packages/bzrlib/plugins/git/remote.py", line 299, in get_refs_container
    lambda x: None, lambda x: trace.mutter("git: %s" % x))
  File "/usr/lib/python2.7/dist-packages/bzrlib/plugins/git/remote.py", line 237, in fetch_pack
    graph_walker, pack_data, progress)
  File "/usr/lib/python2.7/dist-packages/dulwich/client.py", line 471, in fetch_pack
    refs, server_capabilities = self._read_refs(proto)
  File "/usr/lib/python2.7/dist-packages/dulwich/client.py", line 172, in _read_refs
    return refs, set(server_capabilities)
TypeError: 'NoneType' object is not iterable

bzr 2.6.0dev3 on python 2.7.4 (Linux-3.10.0-997-generic-x86_64-with-
    LinuxMint-15-olivia)
arguments: ['/usr/bin/bzr', 'branch',
    'git://<email address hidden>/mathrick/FreshEmptyRepo.git']
plugins: bash_completion[2.6.0dev3], bzrtools[2.5.0],
    changelog_merge[2.6.0dev3], colo[0.4.0], explorer[1.3.0],
    fastimport[0.13.0dev], git[0.6.9], grep[2.6.0dev3], launchpad[2.6.0dev3],
    netrc_credential_store[2.6.0dev3], news_merge[2.6.0dev3], pipeline[1.4.0],
    po_merge[2.6.0dev3], qbzr[0.23.0], rewrite[0.6.4dev], search[1.7.0dev],
    svn[1.2.1], weave_fmt[2.6.0dev3]
encoding: 'utf-8', fsenc: 'UTF-8', lang: 'en_US.UTF-8'

*** 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.