[filmor]

How so? The whole point of unwinding is to gracefully clear up on panics, how did it peak for you?

It's also not like there is much of a choice here. Unwinding across FFI boundaries (e.g. out of the NIF call) is undefined behaviour, so the only other option is aborting on panics.

[throwawaymaths]

Yes. Abort early in unit tests, core dump so it never makes it to prod

[filmor]

The panic is converted to an Erlang error exception. You have to explicitly ignore it to make unit tests pass in spite of it.

I am still interested in the situation you observed.