Manager envvars:RegionOne running task ServerList
Manager envvars:RegionOne ran task ServerList in 0.286849021912s
Traceback (most recent call last):
  File "ok.py", line 9, in <module>
    print cloud.list_servers()
  File "/usr/lib/python2.7/site-packages/shade/openstackcloud.py", line 1121, in list_servers
    self._servers = self._list_servers(detailed=detailed)
  File "/usr/lib/python2.7/site-packages/shade/openstackcloud.py", line 1142, in _list_servers
    return servers
  File "/usr/lib64/python2.7/contextlib.py", line 35, in __exit__
    self.gen.throw(type, value, traceback)
  File "/usr/lib/python2.7/site-packages/shade/_utils.py", line 537, in shade_exceptions
    raise exc.OpenStackCloudException(error_message)
shade.exc.OpenStackCloudException: Error fetching server list on envvars:RegionOne: (Inner Exception: 'str' object has no attribute 'pop')