So I think here it's fine to say 'fatal' in the latter sense, and the fact we immediately mention SIGSEGV clarifies in what sense we mean 'fatal'. The intent here also is that a user would treat this as a fatal event, a thread that accesses a guard area is accessing memory that it shouldn't. However I also see it from your perspective, I mean we say what signal we're sending so it's not hugely necessary and eliminates a possible confusion. Not sure if Alejandro has any objection to this turn of phrase?
