It would seem to be an XS bug - setting the environment var LIST_MOREUTILS_PP=1 makes it go away.
Not for me:
$ LIST_MOREUTILS_PP=1 perl foo
String found where operator expected at (eval 1) line 206, near "Carp:
+:croak "each_arrayref: argument is not an array reference\n""
(Do you need to predeclare Carp::croak?)
String found where operator expected at (eval 1) line 226, near "Carp:
+:croak "each_array: unknown argument '$method' passed to iterator.""
(Do you need to predeclare Carp::croak?)
Use of inherited AUTOLOAD for non-method List::MoreUtils::natatime() i
+s deprecated at foo line 14.
Can't locate auto/List/MoreUtils/natatime.al in @INC (@INC contains: /
+opt/perl/lib/5.10.0/i686-linux-64int-ld /opt/perl/lib/5.10.0 /opt/per
+l/lib/site_perl/5.10.0/i686-linux-64int-ld /opt/perl/lib/site_perl/5.
+10.0 /opt/perl/lib/site_perl/5.8.8 /opt/perl/lib/site_perl .) at foo
+line 14
It runs (with the memory leak) if I don't set LIST_MOREUTILS_PP.