magnum username error

2015-06-09 03:42:31.627 ^[[00;32mDEBUG magnum.cmd.api [^[[00;36m-^[[00;32m] ^[[01;35m^[[00;32m********************************************************************************^[[00m ^[[00;33mfrom (pid=16118) log_opt_values /usr/local/lib/python2.7/dist-packages/oslo_config/cfg.py:2223^[[00m
2015-06-09 03:42:31.627 ^[[00;36mINFO magnum.cmd.api [^[[00;36m-^[[00;36m] ^[[01;35m^[[00;36mserving on http://172.16.155.153:9511^[[00m
172.16.155.153 - - [09/Jun/2015 03:42:32] "GET / HTTP/1.1" 200 326
Traceback (most recent call last):
  File "/usr/lib/python2.7/logging/__init__.py", line 851, in emit
    msg = self.format(record)
  File "/usr/local/lib/python2.7/dist-packages/oslo_log/handlers.py", line 115, in format
    return logging.StreamHandler.format(self, record)
  File "/usr/lib/python2.7/logging/__init__.py", line 724, in format
    return fmt.format(record)
  File "/usr/local/lib/python2.7/dist-packages/oslo_log/formatters.py", line 235, in format
    return logging.Formatter.format(self, record)
  File "/usr/lib/python2.7/logging/__init__.py", line 467, in format
    s = self._fmt % record.__dict__
KeyError: 'user_name'