Attempting to create an enum with __slots__ silently fails. No error is raised if __slots__ are specified, but the usual behaviour of __slots__ does not work as expected. Attributes that are not specified in __slots__ can be freely set:


>>> from enum import Enum
>>> class Color(Enum):
...     __slots__ = ()
...     RED = 0
...     BLUE = 1
...
>>> Color.RED.foo = 'bar'
>>>


Given that enums are rather special, I didn't exactly *expect* this to work -- but it might be good to raise some kind of error if a user attempts to specify __slots__, instead of having it fail silently.