make-method-lambda considered harmful

The CLOS Metaobject Protocol (CLOS MOP) is a specification of how major building blocks of CLOS are implemented in terms of CLOS itself. This enables programmers to subclass meta-level classes and define meta-level state and behavior in an incremental fashion. The benefits of such a meta-level architecture for object systems in general and CLOS in particular are well documented. However, some parts of the CLOS MOP are underspecified or impractical to use. We discuss a particular dark corner of the CLOS MOP, the meta-level function make-method-lambda, whose purpose is to influence the expansion, and thus the semantics, of defmethod forms. We also make concrete suggestions for an alternative design for achieving the functionality that make-method-lambda provides, without any of its drawbacks.