+;;; detection of multiple class options in defclass, reported by Bruno Haible
+(defclass option-class (standard-class)
+ ((option :accessor cl-option :initarg :my-option)))
+(defmethod sb-pcl:validate-superclass ((c1 option-class) (c2 standard-class))
+ t)
+(multiple-value-bind (result error)
+ (ignore-errors (eval '(defclass option-class-instance ()
+ ()
+ (:my-option bar)
+ (:my-option baz)
+ (:metaclass option-class))))
+ (assert (not result))
+ (assert error))
+