Django Migrations: Same migrations being created with makemigrations

The choice parameter should be a deterministic iterable like a list or tuple.

A set is randomized in Python 3.3+ and it can not be a choice.

Change

EVENT_TYPE_CHOICES = {
    (SHIPMENT_EVENT, 'Shipment Event'), ...
}

to

EVENT_TYPE_CHOICES = (
    (SHIPMENT_EVENT, 'Shipment Event'), ...
)