You don't take the test count from Test::Builder or update that count, so you'll always start printing 'ok 1' even if another test has already run. As such, my point stands - in fact, because $current_test is a lexical I can't even hack around the bug. So, no, it does not work fine in the Perl test ecosystem and it needs to be fixed.
From https://github.com/PerlDancer/Dancer2/pull/456