anchor.diff:          (isys:enoent ()
             (ecase if-does-not-exist
               (:error (isys:syscall-error "Directory ~S does not exist" directory))
  -            (nil    nil)))
  +            ((nil)  nil)))
           (isys:eacces ()
             (isys:syscall-error "Search permission is denied for ~S" directory))))))
   
positive.code:                                    parent)))
                         name)))
        (handler-case
            (let ((kind
                   (file-kind directory :follow-symlinks follow-symlinks)))
              (unless (eq :directory kind)
                (isys:syscall-error "~S is not a directory" directory))
              (walk ns -1 ()) t)
  
negative.code:   "Recursively applies the function FN to all files within the
  directory named by the FILE-PATH designator DIRNAME and all of
  the files and directories contained within.  Returns T on success."
    (let ((follow-inner-links
           (and follow-symlinks (not (eql :target follow-symlinks)))))
      (labels ((walk (name depth parent)
                 (incf depth)
                 (let* ((kind
  