I get instead an endless stream of debug output

Well, that's something to work with. Being endless, there must be repeating elements in it. Locate the first repetition, locate the place in your code where it comes from. Provide that snippet with a counter, increment it at each pass, and if it gets to two, invoke a Carp::confess. That should cut things down a bit and provide you with a stack trace you can examine.

From the snippets you provide I can't tell where you are looping, i.e. where your logic is twisted. Can we see the opus in full?

_($_=" "x(1<<5)."?\n".q·/)Oo.  G°\        /
                              /\_¯/(q    /
----------------------------  \__(m.====·.(_("always off the crowd"))."·
");sub _{s./.($e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;$e.e && print}