Comment 0 for bug 1186936

while trying to upgrade to saucy from raring, do-release-upgrade is crashing with the following stack-trace:

Traceback (most recent call last):
  File "/tmp/ubuntu-release-upgrader-jpqsq1/saucy", line 10, in <module>
  File "/tmp/ubuntu-release-upgrader-jpqsq1/DistUpgrade/", line 240, in main
  File "/tmp/ubuntu-release-upgrader-jpqsq1/DistUpgrade/", line 1781, in run
    return self.fullUpgrade()
  File "/tmp/ubuntu-release-upgrader-jpqsq1/DistUpgrade/", line 1676, in fullUpgrade
    if not self.updateSourcesList():
  File "/tmp/ubuntu-release-upgrader-jpqsq1/DistUpgrade/", line 750, in updateSourcesList
    if not self.rewriteSourcesList(mirror_check=True):
  File "/tmp/ubuntu-release-upgrader-jpqsq1/DistUpgrade/", line 726, in rewriteSourcesList
    logging.debug("entry '%s' was disabled (unknown mirror)" % get_string_with_no_auth_from_source_entry(entry))
  File "/tmp/ubuntu-release-upgrader-jpqsq1/DistUpgrade/", line 89, in get_string_with_no_auth_from_source_entry
    return str(tmp)
  File "/tmp/ubuntu-release-upgrader-jpqsq1/DistUpgrade/", line 215, in __str__
    return self.str().strip()
  File "/tmp/ubuntu-release-upgrader-jpqsq1/DistUpgrade/", line 233, in str
    line += " #"+self.comment
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 4: ordinal not in range(128)

My python env is the following:
/usr/bin/env python
Python 2.7.4 (default, Apr 19 2013, 18:28:01)