anchor.diff:  
   ;; Documentation for the function
   ;;
  -;; (defun SOCKET-LISTEN (host port &key reuseaddress backlog) ..)
  +;; (defun SOCKET-LISTEN (host port &key reuseaddress backlog element-type) ..)
   ;;###FIXME: extend with default-element-type
   (setf (documentation 'socket-listen 'function)
         "Bind to interface `host' on `port'. `host' should be the
  
positive.code:   "Create a usocket-server socket type from an
  implementation-specific socket object.
  
  The returned value is a subtype of `stream-server-usocket'."
    (make-instance 'stream-server-usocket
                   :socket socket
                   :element-type element-type))
  
negative.code: 
  (defun make-stream-socket (&key socket stream)
    "Create a usocket socket type from implementation specific socket
  and stream objects.
  
  Sockets returned should be closed using the `socket-close' method or
  by closing the stream associated with the socket.
  "
    (unless socket
      (error 'invalid-socket-error))
    (unless stream
  