|There's more than one way to do things
Maybe you could provide the full http://www.perlmonks.org/index.pl?node_id=310337 URL in your POD. :)
I don't like the idea of your debug() — far too hackish a way to enable deprecation warnings. Probably the best option is to use warnings::register instead. Another idea would be a companion module which merely sets a package variable; it could be then both be used from all the usual places as well as autoenabled by adding -Mdeprecated::warn or some such to PERL5OPT.
Are you putting this on CPAN?
Makeshifts last the longest.