             t t)
   (let ((m prog-mode-map))
     (define-key m [f6] #'recompile))
-  ;; Show trailing whitespace.
-  (set (make-local-variable 'show-trailing-whitespace) t)
+  (setq show-trailing-whitespace t)
   ;; Spellcheck comments and documentation
   ;; From http://mwolson.org/projects/emacs-config/init.el.html
   (flyspell-prog-mode)
-  (whitespace-mode)
   (rainbow-delimiters-mode)
   (hl-line-mode)
   (rainbow-mode)

;; Keep syntax highlighting in the current line.
;; (set-face-foreground 'highlight nil)

(use-package whitespace :ensure t)
(setq whitespace-style '(face lines-tail))

;;  From http://doc.rix.si/org/fsem.html
(defun ar/gnulinuxp ()
  "Return t if the system is a GNU/Linux machine, otherwise nil."

(add-hook 'ediff-quit-hook #'ar/ediff-qh)

(use-package whitespace
  :commands (whitespace-mode global-whitespace-mode)
  :config
  ;; When nil, fill-column is used instead.
  (setq whitespace-line-column nil)
  (setq whitespace-style '(face lines-tail)))
(global-whitespace-mode)

(defun ar/compile-autoclose (buffer string)
  "Hide successful builds window with BUFFER and STRING."
