not trapping signal not sure why, ^C, kill -9, etc

interesting-example.pl

#!/usr/bin/perl -w

$| = 1;
use sigtrap 'handler' => \&sigtrap, 'HUP', 'INT','ABRT','QUIT','TERM'; # ^C, etc
while(1){
 print "Working...\n";
 sleep(2);
}
sub sigtap(){
 print "Caught a signal\n";
 exit(1);
}