On Windows XP, ActiveState 5.10 you will get:
Process completed with exit code 14

There is a problem with "kill", not with ALRM signal.

And SIG INT works also!

#!/usr/bin/perl

use strict;
use warnings;

while (1)
{
  sleep(1);
}
__END__
Terminating on signal SIGINT(2)

Process completed with exit code 2
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....This was CTRL-Break....