Check the environment profile so that we autoload packages that are given as
arguments to "guix environment" but are not in the system or user profile.
Note that the union of Emacs packages in the system, user, and environment
profiles will be autoloaded even when --pure was passed to "guix environment",
because it's not clear how to detect that --pure was given.
* gnu/packages/aux-files/emacs/guix-emacs.el (guix-emacs-autoload-packages):
Add Emacs packages from GUIX_ENVIRONMENT profile.
Signed-off-by: Alex Kost <alezost@gmail.com>