...
    setpgrp(0,0);
    sub killgroup {
        # Make sure all child processes are killed too.
        my $sig = shift;
        local $SIG{$sig} = 'IGNORE'; # don't kill ourselves again
        $Interrupted = 1; 
        kill($sig, -$$);
    };
    local $SIG{INT}  = \&killgroup;
    local $SIG{QUIT} = \&killgroup;
    local $SIG{ABRT} = \&killgroup;
    local $SIG{TERM} = \&killgroup;
    local *CATCHERR = IO::File->new_tmpfile;
    my $pid = open3(gensym, \*CATCHOUT, ">&CATCHERR", "$cmd $args");
...