Using X without a Display Manager

Please note: this page is presently being rewritten by someone very new to nixOS, so do not use it as an example of best practices. The previous content of this page was 2 years out of date and factually incorrect.

To run X11 as a regular user, without `services.xserver.enable = true;` in configuration.nix, do the following:

First, install packages; you need X11 itself, some X11 input modules (e.g. xf86-input-evdev, xf86-input-synaptics, xf86-input-libinput), and possibly video modules as well (xf86-video-intel, xf86-video-ati, xf86-video-nouveau).

You probably want to use DRI acceleration for X; enable it and OpenGL in /etc/nixos/configuration.nix: `hardware.opengl.enable = true;` and `hardware.opengl.driSupport = true;`.

Then, it's just necessary to gather X configuration files into one directory and create a config file that also points X at the correct module paths.

This script does that (though it hard-codes `pkgs` which should instead be computed from the current configuration):

#!/bin/sh
#generate unprivileged user xorg.conf for nixOS
#TODO: obey XDG guidelines rather than assuming ~/.config

mkdir -p ~/.config/xorg.conf.d
cd ~/.config/xorg.conf.d

#failed glob expansions become empty, not literal 'foo/*'
shopt -s nullglob

#TODO: don't hard-code package names!
pkgs="
i0r09miwjk8z9wd2261gh3a3mdzln4w4-xf86-input-evdev-2.10.5
av8542xr7kn44abja120hk3ppd2vp8l8-xf86-video-intel-2017-10-19
8vp93ci2lkcg9c5jh7csfz24npjcnhhx-xf86-input-synaptics-1.9.0
660q2zwjrn0cqkjj6cy861pkazs6yrs0-xorg-server-1.19.6
"

echo 'Section "Files"' > 00-nix-module-paths.conf
for pkg in $pkgs; do
	for conf in /nix/store/"$pkg"/share/X11/xorg.conf.d/*; do 
		ln -s "$conf" ./
	done
	echo '	ModulePath "/nix/store/'"$pkg"'/lib/xorg/modules/"' >> 00-nix-module-paths.conf
done
echo 'EndSection' >> 00-nix-module-paths.conf

You can now start X11 by running:

startx -- :0 -configdir ~/.config/xorg.conf.d