This is a bug in 4.035. While in general it's merely a cosmetic
problem, it often comanifests with a highly undesirable coredumping
problem. Programs known to be affected by the fatal coredump include
plum and pcops. Since perl5 is pretty much a total rewrite, we can
count on it being fixed then, but if anyone tracks down the coredump
problem before then, a significant portion of the Perl world would
rejoice.