* guix/build-system/emacs.scm (default-emacs): Use 'emacs-minimal'. * gnu/packages/emacs.scm (emacs-auctex): Use 'emacs'.
* Makefile.am (MODULES): Add 'guix/build-system/emacs.scm' and 'guix/build/emacs-build-system.scm'. * guix/build-system/emacs.scm: New file. * guix/build/emacs-build-system.scm: New file. * doc/guix.texi (Build Systems): Document it.