libcloud crashs when accessing Swift based object store using Keystone auth API v3

from libcloud.storage.types import Provider
from libcloud.storage.providers import get_driver

cls = get_driver(Provider.OPENSTACK_SWIFT)
driver = cls('USER', 'PASSWORD', ex_force_auth_version='3.x_password',  ex_force_auth_url='https://keystone.cst.de:5001',
ex_tenant_name='signing_service', ex_domain_name='AD', ex_force_service_name='ceph')
container = driver.create_container(container_name='fnord')

Traceback (most recent call last):
  File "D:/DEV/MAIN/Release Management/bin/cstutil/cloudtools.py", line 18, in <module>
    main()
  File "D:/DEV/MAIN/Release Management/bin/cstutil/cloudtools.py", line 14, in main
    container = driver.create_container(container_name='fnord')
  File "C:\Python27\lib\site-packages\libcloud\storage\drivers\cloudfiles.py", line 358, in create_container
    '/%s' % (container_name_encoded), method='PUT')
  File "C:\Python27\lib\site-packages\libcloud\storage\drivers\cloudfiles.py", line 163, in request
    raw=raw)
  File "C:\Python27\lib\site-packages\libcloud\common\openstack.py", line 227, in request
    raw=raw)
  File "C:\Python27\lib\site-packages\libcloud\common\base.py", line 753, in request
    action = self.morph_action_hook(action)
  File "C:\Python27\lib\site-packages\libcloud\common\openstack.py", line 294, in morph_action_hook
    self._populate_hosts_and_request_paths()
  File "C:\Python27\lib\site-packages\libcloud\common\openstack.py", line 338, in _populate_hosts_and_request_paths
    url = self._ex_force_base_url or self.get_endpoint()
  File "C:\Python27\lib\site-packages\libcloud\storage\drivers\cloudfiles.py", line 141, in get_endpoint
    if endpoint:
UnboundLocalError: local variable 'endpoint' referenced before assignment