from perldiag.
This message has not occurred since 5.8.x.
believes it found an infinite loop in the C<@ISA> hierarchy. This is a
crude check that bails out after 100 levels of C<@ISA> depth.
-=item Recursive inheritance detected while looking for method %s
-
-(F) More than 100 levels of inheritance were encountered while invoking
-a method. Probably indicates an unintended loop in your inheritance
-hierarchy.
-
=item Reference found where even-sized list expected
(W misc) You gave a single reference where Perl was expecting a list