Setting environment variables for nix service

[dario]

Hello,


I am a bit confused about how to correctly set up the nix service.
Following the steps in
http://guix.gnu.org/manual/en/guix.html#index-Nix
, the last step is to run

source /run/current-system/profile/etc/profile.d/nix.sh

which takes care about setting the environment variables
correctly. I am
trying to run this command should be run automatically at login.
Two
questions:

1. What is the proper way to do this? I am using gdm and exwm, and
adding the line to any of ~/.profile, ~/.xprofile, ~/.zprofile, or
~/.bash_profile does not seem to have any effect in exwm.

2. Couldn't the nix service take care of this automatically? I'd
be
happy to contribute a corresponding path once I have the answer to
my
first question.


Best regards,

Dario