import from tarball fails with UnicodeDecodeError on non-ascii filenames

Full error:

bzr: ERROR: exceptions.UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 26: ordinal not in range(128)

Traceback (most recent call last):
  File "/usr/lib/python2.6/dist-packages/bzrlib/commands.py", line 853, in exception_to_return_code
    return the_callable(*args, **kwargs)
  File "/usr/lib/python2.6/dist-packages/bzrlib/commands.py", line 1055, in run_bzr
    ret = run(*run_argv)
  File "/usr/lib/python2.6/dist-packages/bzrlib/plugins/bzrtools/command.py", line 13, in run_argv_aliases
    commands.Command.run_argv_aliases(self, argv, alias_argv)
  File "/usr/lib/python2.6/dist-packages/bzrlib/commands.py", line 661, in run_argv_aliases
    return self.run_direct(**all_cmd_args)
  File "/usr/lib/python2.6/dist-packages/bzrlib/commands.py", line 665, in run_direct
    return self._operation.run_simple(*args, **kwargs)
  File "/usr/lib/python2.6/dist-packages/bzrlib/cleanup.py", line 122, in run_simple
    self.cleanups, self.func, *args, **kwargs)
  File "/usr/lib/python2.6/dist-packages/bzrlib/cleanup.py", line 156, in _do_with_cleanups
    result = func(*args, **kwargs)
  File "/usr/lib/python2.6/dist-packages/bzrlib/plugins/bzrtools/command_classes.py", line 506, in run
    do_import(source, tree)
  File "/usr/lib/python2.6/dist-packages/bzrlib/plugins/bzrtools/upstream_import.py", line 276, in do_import
    import_tar(tree, tar_input)
  File "/usr/lib/python2.6/dist-packages/bzrlib/plugins/bzrtools/upstream_import.py", line 171, in import_tar
    import_archive(tree, tar_file)
  File "/usr/lib/python2.6/dist-packages/bzrlib/plugins/bzrtools/upstream_import.py", line 207, in import_archive
    trans_id = tt.trans_id_tree_path(relative_path)
  File "/usr/lib/python2.6/dist-packages/bzrlib/transform.py", line 301, in trans_id_tree_path
    path = self.canonical_path(path)
  File "/usr/lib/python2.6/dist-packages/bzrlib/transform.py", line 1380, in canonical_path
    abs = self._tree.abspath(path)
  File "/usr/lib/python2.6/dist-packages/bzrlib/workingtree.py", line 394, in abspath
    return pathjoin(self.basedir, filename)
  File "/usr/lib/python2.6/posixpath.py", line 70, in join
    path += '/' + b

I was able to do an import from the extracted contents. In #bzr it was suggested that: "the tarball import code assumes all filenames are ascii, but the import from filesystem directory can use the system locale to guess filesystem encoding."