;; Put this code in a file, then compile and load it.
;; Afterward, evaluate (call-frob) and see an error
;; in CLISP.

(defmacro test (&aux (frob (gensym (string '#:frob))))
  `(progn
     (defun ,frob () 42)
     (defun call-frob ()
       (,frob))))

(test)