rlImport should definitely log an ERROR or may be rather WARNING or even just INFO that there are no libraries defined in Makefile but this should not produce exit code other then 0 as this is not a failure. It is actually correct behavior that that no library is imported if no library is defined.
fixed by https://git.fedorahosted.org/cgit/beakerlib.git/commit/?id=d213d2058fb929c6e0022083a7d06504ee951f05