Strengthen typing of choice enums for invalid ops (#862)
Strengthen typing of choice enums for invalid ops (#862)

This makes logging of choice values nicer (we get strings, not ints).
Also, log at V=2 where expected failures occur when using invalid ops.
RJPercival/trillian,gdbelvin/trillian,daviddrysdale/trillian,google/trillian,daviddrysdale/trillian,codingllama/trillian,RJPercival/trillian,google/trillian,Martin2112/trillian,gdbelvin/trillian,daviddrysdale/trillian,AlCutter/trillian,gdbelvin/trillian,Martin2112/trillian,codingllama/trillian,Martin2112/trillian,AlCutter/trillian