NameError in bzrlib/graph.py

I got the following error when pushing up a change to subunit.

$ bzr push lp:subunit
bzr: ERROR: exceptions.NameError: global name 'mutter' is not defined

Traceback (most recent call last):
  File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 893, in run_bzr_catch_errors
    return run_bzr(argv)
  File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 839, in run_bzr
    ret = run(*run_argv)
  File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 539, in run_argv_aliases
    return self.run(**all_cmd_args)
  File "/usr/lib/python2.5/site-packages/bzrlib/builtins.py", line 923, in run
    use_existing_dir=use_existing_dir)
  File "/usr/lib/python2.5/site-packages/bzrlib/push.py", line 162, in _show_push_branch
    stop_revision=revision_id)
  File "/usr/lib/python2.5/site-packages/bzrlib/decorators.py", line 138, in read_locked
    result = unbound(self, *args, **kwargs)
  File "/usr/lib/python2.5/site-packages/bzrlib/branch.py", line 1801, in push
    _override_hook_source_branch=_override_hook_source_branch)
  File "/usr/lib/python2.5/site-packages/bzrlib/branch.py", line 2510, in _run_with_write_locked_target
    result = callable(*args, **kwargs)
  File "/usr/lib/python2.5/site-packages/bzrlib/branch.py", line 1840, in _push_with_bound_branches
    result = self._basic_push(target, overwrite, stop_revision)
  File "/usr/lib/python2.5/site-packages/bzrlib/branch.py", line 1863, in _basic_push
    graph=graph)
  File "/usr/lib/python2.5/site-packages/bzrlib/decorators.py", line 192, in write_locked
    result = unbound(self, *args, **kwargs)
  File "/usr/lib/python2.5/site-packages/bzrlib/remote.py", line 1734, in update_revisions
    self.fetch(other, stop_revision)
  File "/usr/lib/python2.5/site-packages/bzrlib/decorators.py", line 192, in write_locked
    result = unbound(self, *args, **kwargs)
  File "/usr/lib/python2.5/site-packages/bzrlib/branch.py", line 286, in fetch
    pb=nested_pb)
  File "/usr/lib/python2.5/site-packages/bzrlib/remote.py", line 822, in fetch
    return inter.fetch(revision_id=revision_id, pb=pb, find_ghosts=find_ghosts)
  File "/usr/lib/python2.5/site-packages/bzrlib/decorators.py", line 192, in write_locked
    result = unbound(self, *args, **kwargs)
  File "/usr/lib/python2.5/site-packages/bzrlib/repository.py", line 2974, in fetch
    find_ghosts=find_ghosts).get_keys()
  File "/usr/lib/python2.5/site-packages/bzrlib/decorators.py", line 138, in read_locked
    result = unbound(self, *args, **kwargs)
  File "/usr/lib/python2.5/site-packages/bzrlib/repository.py", line 3012, in search_missing_revision_ids
    return self._walk_to_common_revisions([revision_id])
  File "/usr/lib/python2.5/site-packages/bzrlib/repository.py", line 2544, in _walk_to_common_revisions
    if set(target_graph.get_parent_map(revision_ids)) == revision_ids:
  File "/usr/lib/python2.5/site-packages/bzrlib/graph.py", line 93, in get_parent_map
    new_found = parents_provider.get_parent_map(remaining)
  File "/usr/lib/python2.5/site-packages/bzrlib/graph.py", line 168, in get_parent_map
    mutter('re-retrieved revisions: %d of %d',
NameError: global name 'mutter' is not defined

bzr 1.11dev on python 2.5.2 (linux2)
arguments: ['/usr/bin/bzr', '-Dhpss', 'push', 'lp:subunit']
encoding: 'UTF-8', fsenc: 'UTF-8', lang: 'en_AU.UTF-8'
plugins:
  avahi /usr/lib/python2.5/site-packages/bzrlib/plugins/avahi [0.3dev]
  bzrtools /home/jml/.bazaar/plugins/bzrtools [1.10]
  dbus /usr/lib/python2.5/site-packages/bzrlib/plugins/dbus [unknown]
  gtk /usr/lib/python2.5/site-packages/bzrlib/plugins/gtk [0.95.0.final.1]
  launchpad /usr/lib/python2.5/site-packages/bzrlib/plugins/launchpad [unknown]
  loom /home/jml/.bazaar/plugins/loom [1.4dev]
  lpreview /home/jml/.bazaar/plugins/lpreview [unknown]
  pqm /home/jml/.bazaar/plugins/pqm [1.4dev]
*** Bazaar has encountered an internal error.
    Please report a bug at https://bugs.launchpad.net/bzr/+filebug
    including this traceback, and a description of what you
    were doing when the error occurred.
HPSS calls: 13 <bzrlib.smart.medium.SmartSSHClientMedium object at 0x18b7450>