Im having exactly this error, i'm just a rookie developer and tried this change you mention but still does not work for me, could you lend a hand?
from ocu.cache import cache
File "ocu/cache.py", line 130, in <module>
cache = Cache()
File "ocu/cache.py", line 42, in __init__
self.refresh()
File "ocu/cache.py", line 110, in refresh
if self.get('event_blobs') != event_blobs:
File "ocu/cache.py", line 77, in get
return self.__dict__.get([key])
TypeError: unhashable type: 'list'