anchor.diff:  (defmethod record-failure ((type (eql :macro))
                              form actual expected extras test)
     "Return an instance of a macro failure result."
  -  (call-next-method 'macro-result form actual expected extras test))
  +  (%record-failure 'macro-result form actual expected extras test))
   
   (defclass boolean-result (failure-result)
     ()
  
positive.code: (defmethod record-failure ((type (eql :result))
                             form actual expected extras test)
    "Return an instance of a boolean failure result."
    (call-next-method 'boolean-result form actual expected extras test))
  
  (defclass output-result (failure-result)
    ()
  
negative.code: (defmethod record-failure ((type (eql :output))
                             form actual expected extras test)
    "Return an instance of an output failure result."
    (%record-failure 'output-result form actual expected extras test))
  
  (defun internal-assert
         (type form code-thunk expected-thunk extras test)
  