Traceback (most recent call last):
  File "/usr/lib/python2.7/site-packages/cliapp/app.py", line 190, in _run
    self.process_args(args)
  File "/src/morph/morphlib/app.py", line 267, in process_args
    cliapp.Application.process_args(self, args)
  File "/usr/lib/python2.7/site-packages/cliapp/app.py", line 539, in process_args
    method(args[1:])
  File "/src/morph/morphlib/plugins/list_artifacts_plugin.py", line 67, in list_artifacts
    repo, ref, system_filename)
  File "/src/morph/morphlib/plugins/list_artifacts_plugin.py", line 110, in list_artifacts_for_system
    artifact.cache_key = ckc.compute_key(artifact)
  File "/src/morph/morphlib/cachekeycomputer.py", line 39, in compute_key
    ret = self._hash_id(self.get_cache_id(source))
  File "/src/morph/morphlib/cachekeycomputer.py", line 78, in get_cache_id
    cacheid = self._calculate(source)
  File "/src/morph/morphlib/cachekeycomputer.py", line 87, in _calculate
    for a in source.dependencies],
AttributeError: 'Artifact' object has no attribute 'dependencies'