anchor.diff:  
   (define-condition ns-unknown-error (ns-error)
     ((real-error :initarg :real-error
  -               :accessor ns-real-error))
  +               :accessor ns-real-error
  +               :initform nil))
     (:report (lambda (c stream)
                (typecase c
                  (simple-condition
  
positive.code: 
  (define-condition unknown-error (socket-error)
    ((real-error :initarg :real-error
                 :accessor usocket-real-error))
    (:report (lambda (c stream)
               (typecase c
                 (simple-condition
  
negative.code:   (ns-condition))
  
  (define-condition ns-unknown-condition (ns-condition)
    ((real-condition :initarg :real-condition
                     :accessor ns-real-condition
                     :initform nil))
    (:documentation "Condition raised when there's no other - more applicable -
  condition available."))
  
  