In 5.12 rjbs deprecated "use UNIVERSAL qw(can isa ...)" with a warning, in v5.22 Dagfinn made this a fatal error. I've just pushed a smoke-me branch to remote UNIVERSAL::import from that package, and make its (no)?import a fatal error via a hack to gv.c: http://perl5.git.perl.org/perl.git/commitdiff/8804321d The motivation here is that someone doing "use UNIVERSAL;" in some module shouldn't make $pkg->can("import") true for any value of $pkg in your program. But technically this does break backwards compatibility without a deprecation cycle. Because "use UNIVERSAL;" isn't an error today, and some code on the CPAN redundantly uses that. So what do you think we should do about that? Should we wait until around 2020 until $pkg->can("import") won't be true at a distance by going through the full warn/error cycle for this, or just try to push this to blead and see if it's a big deal? The fix to broken code is trivial, just remove the "use" line for UNIVERSAL, or if you feel you must have it import it with a () argument.Thread Next