sigtrap pragma initializes some default signal handlers that print
a stack dump of your Perl program, then sends itself a SIGABRT. This
provides a nice starting point if something horrible goes wrong.
By default, handlers are installed for the ABRT, BUS, EMT, FPE, ILL, PIPE, QUIT, SEGV, SYS, TERM, and TRAP signals.
See Pragmatic Modules.