Comment 2 for bug 810540

jr@gallus:~/src/libdbusmenu-qt/udd-test/libdbusmenu-qt>bzr -Derror merge-upstream --version 0.2.0 http://launchpad.net/libdbusmenu-qt/trunk/0.2.0/+download/libdbusmenu-qt-0.2.0.tar.bz2
Using distribution unstable
bzr: ERROR: bzrlib.errors.BzrError: must supply file_id or path

Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 926, in exception_to_return_code
    return the_callable(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 1126, in run_bzr
    ret = run(*run_argv)
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 691, in run_argv_aliases
    return self.run(**all_cmd_args)
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 713, in run
    return self._operation.run_simple(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/cleanup.py", line 135, in run_simple
    self.cleanups, self.func, *args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/cleanup.py", line 165, in _do_with_cleanups
    result = func(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/plugins/builddeb/cmds.py", line 656, in run
    contains_upstream_source)
  File "/usr/lib/python2.7/dist-packages/bzrlib/plugins/builddeb/util.py", line 663, in guess_build_type
    source_format = get_source_format(tree)
  File "/usr/lib/python2.7/dist-packages/bzrlib/plugins/builddeb/util.py", line 644, in get_source_format
    return tree.get_file_text(tree.path2id("debian/source/format")).strip()
  File "/usr/lib/python2.7/dist-packages/bzrlib/workingtree.py", line 528, in get_file_text
    my_file = self.get_file(file_id, path=path, filtered=filtered)
  File "/usr/lib/python2.7/dist-packages/bzrlib/workingtree.py", line 513, in get_file
    return self.get_file_with_stat(file_id, path, filtered=filtered)[0]
  File "/usr/lib/python2.7/dist-packages/bzrlib/workingtree.py", line 519, in get_file_with_stat
    path = self.id2path(file_id)
  File "/usr/lib/python2.7/dist-packages/bzrlib/decorators.py", line 140, in read_locked
    result = unbound(self, *args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/workingtree_4.py", line 447, in id2path
    entry = self._get_entry(file_id=file_id)
  File "/usr/lib/python2.7/dist-packages/bzrlib/workingtree_4.py", line 354, in _get_entry
    raise errors.BzrError('must supply file_id or path')
BzrError: must supply file_id or path