Should guix-emacs-autoload-packages use GUIX_ENVIRONMENT?

[Kyle Meyer <kyle@kyleam.com>]

Hello,

I noticed that Emacs packages from the user's profile leak into guix
environment calls.

For example, when I run

    $ guix environment --pure --ad-hoc emacs -- emacs -q

load-path contains the Emacs packages from my main profile.

I expected it to use GUIX_ENVIRONMENT instead (something like the patch
below, I think).

Does guix-emacs-autoload-packages ignore GUIX_ENVIRONMENT by design?  I
suppose one downside of honoring GUIX_ENVIRONMENT is that, if the --pure
flag isn't passed and the package arguments aren't Emacs-related, a user
may be surprised that their Emacs packages are no longer available in
newly created Emacs instances.

Thanks.

-- >8 --
diff --git a/gnu/packages/aux-files/emacs/guix-emacs.el b/gnu/packages/aux-files/emacs/guix-emacs.el
index 2bbd639ff..2d0d50e11 100644
--- a/gnu/packages/aux-files/emacs/guix-emacs.el
+++ b/gnu/packages/aux-files/emacs/guix-emacs.el
@@ -87,9 +87,11 @@ (defun guix-emacs-autoload-packages (&rest profiles)
   (interactive (list (if (fboundp 'guix-read-package-profile)
                          (funcall 'guix-read-package-profile)
                        guix-user-profile)))
-  (let ((profiles (or profiles
-                      (list "/run/current-system/profile"
-                            guix-user-profile))))
+  (let* ((env      (getenv "GUIX_ENVIRONMENT"))
+         (profiles (or profiles
+                       (and env (list env))
+                       (list "/run/current-system/profile"
+                             guix-user-profile))))
     (dolist (profile profiles)
       (let ((dirs (guix-emacs-directories profile)))
         (when dirs
-- 
2.13.3