There appears to be a typo in the requires part of this interface:
2018-10-16 13:30:14 ERROR juju-log secrets-storage:11: Hook error:
Traceback (most recent call last):
File "/var/lib/juju/agents/unit-barbican-vault-0/.venv/lib/python3.6/site-packages/charms/reactive/__init__.py", line 73, in main
bus.dispatch(restricted=restricted_mode)
File "/var/lib/juju/agents/unit-barbican-vault-0/.venv/lib/python3.6/site-packages/charms/reactive/bus.py", line 390, in dispatch
_invoke(other_handlers)
File "/var/lib/juju/agents/unit-barbican-vault-0/.venv/lib/python3.6/site-packages/charms/reactive/bus.py", line 359, in _invoke
handler.invoke()
File "/var/lib/juju/agents/unit-barbican-vault-0/.venv/lib/python3.6/site-packages/charms/reactive/bus.py", line 181, in invoke
self._action(*args)
File "/var/lib/juju/agents/unit-barbican-vault-0/charm/reactive/barbican_vault_handlers.py", line 38, in ssc
secrets_storage.request_secret_backend('charm-barbican-vault')
File "/var/lib/juju/agents/unit-barbican-vault-0/charm/hooks/relations/vault-kv/requires.py", line 59, in request_secret_backend
relation.to_publish['access_address'] = self.endpoint_address
File "/var/lib/juju/agents/unit-barbican-vault-0/charm/hooks/relations/vault-kv/requires.py", line 45, in endpoint_address
self.expand_name({'endpoint_name'})
File "/var/lib/juju/agents/unit-barbican-vault-0/.venv/lib/python3.6/site-packages/charms/reactive/endpoints.py", line 190, in expand_name
flag = 'endpoint.{endpoint_name}.' + flag
TypeError: must be str, not set
There appears to be a typo in the requires part of this interface: