anchor.diff:                                   (type (eql 'unix-path))
                                    &key (start 0) end
                                    as-directory expand-user)
  -  (let* ((expansion (if expand-user
  -                        (%expand-user-directory (subseq namestring start end))
  -                        (subseq namestring start end)))
  +  (let* ((actual-namestring (subseq namestring start end))
  +         (expansion (or (when expand-user
  +                          (ignore-some-conditions (isys:posix-error)
  +                            (%expand-user-directory actual-namestring)))
  +                        actual-namestring))
            (components (remove "." (split-directory-namestring expansion)
                                :test #'string=))
            (dirname (if as-directory components (butlast components)))
  
positive.code: ;;;-------------------------------------------------------------------------
  
  (defparameter *default-file-path-defaults*
    (parse-file-path (isys:%sys-getcwd) :as-directory t))
  
  (defparameter *default-execution-path*
    (mapcar (lambda (p)
  
negative.code:                  (eql :relative (first directory))
                   (stringp (second directory))))
      (let ((dirs (split-directory-namestring
                   (handler-case
                       (%expand-user-directory (second directory))
                     (isys:posix-error () (return* path))))))
        (setf directory
              (append (list :absolute) dirs (cddr directory)))))
    (values path))
  