anchor.diff:  
   (defun read-symlink (pathspec)
     "Returns the file-path pointed to by the symbolic link
  -designated by PATHSPEC.  If the link is relative, then the
  +designated by PATHSPEC. If the link is relative, then the
   returned file-path is relative to the link, not
   *DEFAULT-FILE-PATH-DEFAULTS*.
   
   Signals an error if PATHSPEC is not a symbolic link."
     ;; Note: the previous version tried much harder to provide a buffer
  -  ;; big enough to fit the link's name.  OTOH, %SYS-READLINK stack
  +  ;; big enough to fit the link's name. OTOH, %SYS-READLINK stack
     ;; allocates on most lisps.
     (file-path (isys:%sys-readlink
                 (file-path-namestring
  
positive.code:        (%obj-getenv env name)))))
  
  (defun (setf environment-variable) (value name &optional env &key (overwrite t))
    (let ((value (string value))
          (name (string name)))
      (etypecase env
  
negative.code: 
  (defun directory-exists-p (pathspec)
    "Checks whether the file named by the file-path designator
  PATHSPEC exists and is a directory. Returns its truename
  if this is the case, NIL otherwise. Follows symbolic links."
    (nth-value 0 (file-exists-p pathspec :directory)))
  
  (defun good-symlink-exists-p (pathspec)
  