redirecting output from a format

[mpeters]

I am trying to redirect the output from the Test::Harness::runtests() method into a scalar. I'm using IO::Scalar to do the job of redirecting STDOUT and it works just like expected, except for one spot. When a subtest fails, Test::Harness uses a format (associated with STDOUT) to create the pretty report that shows which subtests failed, etc. I would also like to capture this report into my scalar, but I haven't been able to do it.

    my $test_output;
    my $IO = IO::Scalar->new(\$test_output);
    $IO->format_name('STDOUT');
    $IO->format_top_name('STDOUT_TOP');
    select($IO);
    eval {
        runtests(@testfiles);
    };
    $test_output .= $@ if ($@);
    select(STDOUT);

After doing this, my scalar ($test_output) does not contain the failure report and neither is it printed to the screen. When I try this:

    my $test_output;
    tie(*STDOUT, 'IO::Scalar', \$test_output);
    eval {
        runtests(@testfiles);
    };
    $test_output .= $@ if ($@);
    untie(*STDOUT);

I end up with the same data in $test_output, but the failure report is printed to the screen. Still not what I want... Any suggestions?