Surprisingly, this generally default value was not set on Jean-Marc's brand new Mac OS.

As a consequence auctex, among other things, was not found. I don't
know why but let's avoid relying on default value anyway.

module2/ressources/rr_org/init.el

@@ -51,6 +51,8 @@
 ;;                              " -Dhttp.proxyPort=" proxy-port)))
 
 (package-initialize)
+(add-to-list 'package-archives
+		 '("gnu" . "https://elpa.gnu.org/packages/"))
 (add-to-list 'package-archives
 		 '("melpa-stable" . "http://stable.melpa.org/packages/"))
 (add-to-list 'package-archives

module2/ressources/rr_org/init.org

@@ -74,6 +74,8 @@ document, simply =M-x org-babel-tangle=.
 ** Use melpa-stable (preferred) and melpa in addition to the default GNU archive
 #+BEGIN_SRC emacs-lisp :tangle init.el
 (package-initialize)
+(add-to-list 'package-archives
+		 '("gnu" . "https://elpa.gnu.org/packages/"))
 (add-to-list 'package-archives
 		 '("melpa-stable" . "http://stable.melpa.org/packages/"))
 (add-to-list 'package-archives