My intention was to proof a bug in short code.

There is no possible explanation for an undefined value after the loop. Hence a bug.

> Here you are initializing a seperate variable before the until, which is getting reset by the my inside the until.

This statement doesn't really make sense, if the variables are different they can't reset each other.

As already explained does my have a compile time and a runtime effect, which are inconsistent in this case.

> Seems like two different (but related) bugs to me.

No. Everything else was explained.

> My original code:

> $count++ until my %boxes = fit($count, $quota, @sizes);

Thanks, nice example.

FWIW a workaround is to put the my declaration right before the loop.