I am try to add some special keywords face. ruby-local-enable-extra-keywords is not defined.

[zw963]

(defun rinari-highlight-keywords (keywords)
  "Highlight the passed KEYWORDS in current buffer.
Use `font-lock-add-keywords' in case of `ruby-mode' or
`ruby-extra-keywords' in case of Enhanced Ruby Mode."
  (if (boundp 'ruby-extra-keywords)
      (progn
        (setq ruby-extra-keywords (append ruby-extra-keywords keywords))
        (ruby-local-enable-extra-keywords))
    (font-lock-add-keywords
     nil
     (list (list
            (concat "\\(^\\|[^_:.@$]\\|\\.\\.\\)\\b"
                    (regexp-opt keywords t)
                    (eval-when-compile (if (string-match "\\_>" "ruby")
                                           "\\_>"
                                         "\\>")))
            (list 2 'font-lock-builtin-face))))))

[zw963]

I see, it defined from Enhanced-Ruby-Mode. Thanks.