anchor.diff:         (%write-simple-array-ub8 stream seq start end))
         (string
          (stream-write-string stream seq start end))
  -      ((vector ub8)
  +      (ub8-vector
          (%write-vector-ub8 stream seq start end))
         (vector
          (%write-vector stream seq start end)))))
  
positive.code: (defmethod stream-write-char ((stream dual-channel-gray-stream)
                                (character character))
    (%flush-obuf-if-needed stream)
    (if (eql character #\Newline)
        (%write-line-terminator stream (ioenc:ef-line-terminator (external-format-of stream)))
        ;; FIXME: avoid consing a string here. At worst, declare it dynamic-extent
        (stream-write-string stream (make-string 1 :initial-element character))))
  
negative.code:               (when (zerop timeout-var) (return-from %write-n-bytes (values nil :timeout)))))))))
  
  (defun %flush-obuf (buf fd &optional timeout)
    (declare (type iobuf buf))
    (let ((bytes-written 0))
      (flet ((write-once ()
               (let ((num (handler-case
  