Events from a Library, which emit enum type, are ignored

[fleupold]

We are using django-eth-events to react to events from the dfusion smart contract in our infrastructure layer.

Recently, we split a large base contract into a thin wrapper and a library contract (https://github.com/gnosis/dex-contracts/pull/119).

Before the change, we were emitting this event with an enum type as a parameter without a problem (django-eth-events would notify our event listener)

After the change, the event (amongst others) have moved into the library (cf. here). While the other events are still subscribed to correctly (our listener gets invoked), the StateTransition event is now ignored by django-eth-events.

It turns out that it can be worked around by casting from the enum type to an integer type like shown in: https://github.com/gnosis/dex-contracts/pull/127/files#diff-6d788d5366b87afae30a24d26f5b3b0d

Is this expected?