evalを*buffer-package*で実行するようにしたついでにそれっぽいものを書いてみた。

gistfile1.lisp

;;; show *buffer-package* in buffer bar
(pushnew '(show-lisp-package-mode . *buffer-package*)
	 *minor-mode-alist* :key #'car)

(defvar-local show-lisp-package-mode nil)

(defun show-lisp-package-mode (&optional (arg nil sv))
  (interactive "p")
  (ed::toggle-mode 'show-lisp-package-mode arg sv)
  (update-mode-line t)
  t)

(add-hook 'ed:*lisp-mode-hook* 'show-lisp-package-mode)
(add-hook 'ed:*lisp-interaction-mode-hook* 'show-lisp-package-mode)