https://docs.python.org/3.6/library/uuid.html#uuid.UUID

uuid.uuid1(node=None, clock_seq=None)

Generate a UUID from a host ID, sequence number, and the current time. If node is not given, getnode() is used to obtain the hardware address. If clock_seq is given, it is used as the sequence number; otherwise a random 14-bit sequence number is chosen.


^^

This neglects to mention that if you call uuid1() in quick succession with no parameters, you can get a repeat uuid.

I had a bug because of this.

It would have been nice if the docs mentioned the fact directly. 

It's only a sentence to add, and would have saved a lot of time.