anchor.diff:                            &allow-other-keys)
     (:method ((compiler T) from to &rest args &key)
       (apply #'c-preprocess *default-compiler* from to args))
  -  (:method ((c-compiler c-compiler) from to &key (warnings :all)
  +  (:method ((c-compiler c-compiler) from to &key warnings
                                                    source
                                                    standard
                                                    options
  
positive.code: 
  (defgeneric invoke (c-compiler args &key output error-output &allow-other-keys)
    (:method (c-compiler args &rest kargs &key (output T) (error-output T))
      (apply #'uiop:run-program (etypecase args
                                  (list (cons (executable c-compiler) (mapcar #'externalize args)))
                                  (string (format NIL "~a ~a" (executable c-compiler) args)))
             :output output :error-output error-output kargs)))
  
  (defvar *default-compiler* (make-instance 'c-compiler))
  
  
negative.code:                         &allow-other-keys)
    (:method ((compiler T) from to &rest args &key)
      (apply #'c-assemble *default-compiler* from to args))
    (:method ((c-compiler c-compiler) from to &key warnings
                                                   optimize
                                                   debug
                                                   source
  