If you my %stopper, it will stop the autovivification:

Well, that would be strange. Very, very strange. Do you think that happens because there's an explicite check in perl that says "hmmm, we are doing autovivification of a secondary key in the hash, but the parent hash is a lexical, so let's not do it", or that you've hit a strange bug?

Or could it be that autovivification is happening? And you are just giving the wrong argument to Dumper? Try giving \%{"stopper"} as argument to Dumper.

Abigail