Hacking Test::Harness

So we need to change Test::Harness.
Now where's the summary line?

sub _show_results {
    my($tot, $failedtests) = @_;

    my $pct;
    my $bonusmsg = _bonusmsg($tot);

    if (_all_ok($tot)) {
        print "All tests successful$bonusmsg.\n"; # <--- here
    }
    elsif (!$tot->{tests}){
        die "FAILED--no tests were run for some reason.\n";
    }
    elsif (!$tot->{max}) {
        my $blurb = $tot->{tests}==1 ? "script" : "scripts";
        die "FAILED--$tot->{tests} test $blurb could be run, ".
            "alas--no output ever seen\n";
    }
    else {
        $pct = sprintf("%.2f", $tot->{good} / $tot->{tests} * 100);
        my $percent_ok = 100*$tot->{ok}/$tot->{max};
        my $subpct = sprintf " %d/%d subtests failed, %.2f%% okay.",
                              $tot->{max} - $tot->{ok}, $tot->{max},
                              $percent_ok;

        my($fmt_top, $fmt) = _create_fmts($failedtests);

        # Now write to formats
        for my $script (sort keys %$failedtests) {
          $Curtest = $failedtests->{$script};
          write;
        }
        if ($tot->{bad}) {
            $bonusmsg =~ s/^,\s*//;
            print "$bonusmsg.\n" if $bonusmsg;
            die "Failed $tot->{bad}/$tot->{tests} test scripts, $pct% okay.".
                "$subpct\n";
        }
    }

    printf("Files=%d, Tests=%d, %s\n",
           $tot->{files}, $tot->{max}, timestr($tot->{bench}, 'nop'));
}

Problems

A monolithic function with just one line to change.
There isn't an object instance for easy inheritance and over-riding.
A lot of similar issues in the rest of the code.