Opps. I accidentally posted the version with warnings enabled. Thanks for pointing it out, and motivating me to actually check that it is not an issue (Whew). :-)
Here is an excerpt from perldiag that explains the warning, and why it is surfaced.
Deep recursion on subroutine ``%s''
(W recursion) This subroutine has called itself (directly or
indirectly) 100 times more than it has returned. This
probably indicates an infinite recursion, unless you're
writing strange benchmark programs, in which case it indicates
something else.