Re:pcl erroring out for some unknown reason

[Darrell <shane%blackcomb@rand.org>]

>> At random places where I am defining methods and classes I will get 
>> an error message similar to the following:
>> 
>> Error: No matching method for the generic-function 
>> #<Function CLASS-PRECEDENCE-LIST @ #x5a3519>,
>> when called with arguments (NIL).
>> 
>> After the error, PCL is completely corrupt.  The error will be issued 
>> from then on whenever an instance is instantiated, including classes 
>> and methods.  Has anyone experienced this error before?  Any fixes, 
>> or guidance will be most appreciated.


;;; I now know why this error message was issued.  Consider the following:

(defclass c1 () ())

;;; Notice the incorrect lambda list.
(defmethod shared-initialize :after ((self c1) &rest ignore)
  (declare (ignore slot-names ignore))
  (format t "After c1 shared-initialize method.~%"))

(defmethod shared-initialize :before ((self c1) slot-names &rest ignore)
  (declare (ignore ignore))
  (format t "Before c1 shared-initialize method.~%"))

;;; When compiling the above class and two methods, PCL will issue the 
;;; error message:

Error: No matching method for the generic-function #<Function
CLASS-PRECEDENCE-LIST @ #x59eda1>,
when called with arguments (NIL).

;;; when trying to compile the last method.  That is an error is signaled 
;;; when the next method of the generic function is compiled; not when the 
;;; erroneous method is.  The error message is extremely misleading 
;;; especially when the two methods are separated by many other forms 
;;; or are defined in separate files.


To all those who tried to help, thanks.

Darrell Shane