Comment 2 for bug 1605954

This fails to retrace:

07/24/16 05:33:08: Installing extra package youker-assistant to get ExecutablePath
Traceback (most recent call last):
  File "apport/bin/apport-retrace", line 335, in <module>
    gen_source_stacktrace(report, apt_root)
  File "apport/bin/apport-retrace", line 183, in gen_source_stacktrace
    result += frame + '\n' + get_code(srcdir, os.path.basename(m.group(1)), int(m.group(2)))
  File "apport/bin/apport-retrace", line 137, in get_code
    files = find_file_dir(filename, srcdir, 1)
  File "apport/bin/apport-retrace", line 125, in find_file_dir
    for root, dirs, files in os.walk(dir):
  File "/usr/lib/python2.7/os.py", line 294, in walk
    for x in walk(new_path, topdown, onerror, followlinks):
  File "/usr/lib/python2.7/os.py", line 294, in walk
    for x in walk(new_path, topdown, onerror, followlinks):
  File "/usr/lib/python2.7/os.py", line 294, in walk
    for x in walk(new_path, topdown, onerror, followlinks):
  File "/usr/lib/python2.7/os.py", line 284, in walk
    if isdir(join(top, name)):
  File "/usr/lib/python2.7/posixpath.py", line 80, in join
    path += '/' + b
UnicodeDecodeError: 'ascii' codec can't decode byte 0xe8 in position 1: ordinal not in range(128)