Using AUCTeX from ELPA-devel

It is possible to use the latest development version of AUCTeX conveniently as a package installed from GNU-devel ELPA. This package tracks the latest change in AUCTeX Git repository and is intended for brave users who want to test the distribution and report possible issues. The following addition to user-init-file instructs Emacs to change the archive AUCTeX is installed from:

(add-to-list 'package-archives
             '("elpa-devel" . "https://elpa.gnu.org/devel/") t)
(setq package-archive-priority
      '(("elpa" . 10)
        ("elpa-devel" . 5)))
(setq package-pinned-packages
      '((auctex . "elpa-devel")))

In a nutshell, the code adds the new archive to the list of know archives under the name ‘elpa-devel’, gives it a lower priority than the regular archive, and instructs Emacs to fetch only AUCTeX from the new archive and don’t bother with other packages installed.