Time::HiRes::alarm(0); しないと意図しない箇所で die する例

sigalrm.pl

#!/usr/bin/env perl
use strict;
use warnings;

use POSIX qw(SIGALRM);
use Time::HiRes;

print "begin\n";

eval {
    POSIX::sigaction(        
        SIGALRM, POSIX::SigAction->new(sub { die "timeout\n" })
    ) or die "can't set SIGALRM handler: $!\n";
    Time::HiRes::alarm(10);
    sleep(8);
};
if ($@) {
    print $@;
}
sleep(4);

print "end\n";