Amazon AWS backup fails

[Toshi Ide]

Traceback (most recent call last):
  File "/usr/bin/duplicity", line 1500, in <module>
    with_tempdir(main)
  File "/usr/bin/duplicity", line 1494, in with_tempdir
    fn()
  File "/usr/bin/duplicity", line 1327, in main
    action = commandline.ProcessCommandLine(sys.argv[1:])
  File "/usr/lib/python2.7/dist-packages/duplicity/commandline.py", line 1047, in ProcessCommandLine
    globals.backend = backend.get_backend(args[0])
  File "/usr/lib/python2.7/dist-packages/duplicity/backend.py", line 221, in get_backend
    obj = get_backend_object(url_string)
  File "/usr/lib/python2.7/dist-packages/duplicity/backend.py", line 207, in get_backend_object
    return factory(pu)
  File "/usr/lib/python2.7/dist-packages/duplicity/backends/_boto_single.py", line 161, in __init__
    self.resetConnection()
  File "/usr/lib/python2.7/dist-packages/duplicity/backends/_boto_single.py", line 183, in resetConnection
    self.conn = get_connection(self.scheme, self.parsed_url, self.storage_uri)
  File "/usr/lib/python2.7/dist-packages/duplicity/backends/_boto_single.py", line 97, in get_connection
    assert scheme == 's3'
AssertionError