I'd say don't use do. If you've got the test notebook you can find the sample for a smoke test on p57, something like this (incomplete code)-

my $strap = Test::Harness::Straps->new();

for my $test ( <path/to/tests/*.t> )
{
    # warn/debug "Running test: $test\n";
    my %result = $strap->analyze_file( $test );
    next if $result{passing};
    # Build report on failing results here
    # to present in an Ajax'd div or something.
}
[download]

You might accidentally fix it by not using do and you should at least track the problem down to a single test otherwise.

Update: s/frame/div/; I did not mean a literal HTML frame.