"Caught error: Circular reference detected" on Nova API when spinning up a VM with Rally Testing Framework

Issue

• When sending this request on the Nova API via python-novaclient:

  URL:  /servers
  BODY: {'endpoint_filter': {'service_type': 'compute', 'interface': 'publicURL'}, 'client_name': 'python-novaclient', 'headers': {'Accept': 'application/json'}, 'json': {'server': {'min_count': 1, 'flavorRef': '3e03b806-aa8f-4fc0-a52e-00ab8ecf94e1', 'name': 's_rally_87b0d541_NJz7xnty', 'imageRef': 'e4206d8e-7687-45d5-b38a-96e5763b2d89', 'max_count': 1}}, 'user_agent': 'python-novaclient', 'endpoint_override': u'https://endpoint.example.com:13774/v2.1', 'raise_exc': False, 'client_version': '16.0.0'}
  

• I get this error from Nova:

  /var/log/nova/nova-api.log:2021-02-08 19:29:10.874 712041 ERROR nova.api.openstack [req-7078f79d-230f-4703-a9e3-9ed36b71393a 82f51202eb774cab9b4dfd511148a374 797f85a5cf5a45f39d151d963787833c - default default] Caught error: Circular reference detected