How to set DISPLAY when using Niri through Display Manager and xwayland-satellite through systemd?

[calebperkins]

I am using Arch Linux and greetd. I'd like to start Niri as a session, through my Display Manager. I'd also like to start xwayland-satellite with the included systemd service file.

I've enabled the xwayland-satellite systemd service and added DISPLAY to the Niri config.idl environment file : https://github.com/YaLTeR/niri/wiki/Configuration:-Miscellaneous#environment

However, it seems that when you start Niri as a session through a Display Manager, the variables in environment do not get picked up. DISPLAY does not get set when I try reading it in a terminal launched by Niri, for example, and Steam complains it cannot get a connection to X11.

Is there a way to get this setup working?

Steps to reproduce

1. Add this to Niri config:

environment {
    DISPLAY ":0"
}

2. Enable the xwayland-satellite systemd service:

systemctl --user enable xwayland-satellite.service

3. log out, start Niri as a session through greetd or whatever:

tuigreet --cmd niri

4. DISPLAY is not set, Steam complains, etc

echo $DISPLAY # nothing

Workaround

1. Create the file ~/.config/environment.d/niri.conf
2. add DISPLAY=:0 to this file
3. log out and log back in through Display Manager

However, this workaround is not great because it interferes with other window managers and desktop environments like Hyprland that set DISPLAY through their own mechanism.

[Supreeeme]

Hmm, this could be related to the fact that the service file shipped with satellite binds to/starts with graphical-session.target, but I'd guess a display manager also begins graphical-session.target (I don't use one). The output of systemctl --user status xwayland-satellite would be useful here - you can compare the start time with that of systemctl - -user status niri.

Something to try would be replacing all the graphical-session.target in the service file with niri.service.

[calebperkins]

● niri.service - A scrollable-tiling Wayland compositor
     Loaded: loaded (/usr/lib/systemd/user/niri.service; static)
     Active: active (running) since Tue 2025-05-20 19:32:33 PDT; 24s ago
 Invocation: 9bea49a2d0d947fe847099a4113c416c
   Main PID: 7075 (niri)
      Tasks: 32 (limit: 37176)
     Memory: 67.9M (peak: 68.6M)
        CPU: 500ms
     CGroup: /user.slice/user-1000.slice/[email protected]/session.slice/niri.service
             └─7075 /usr/bin/niri --session

May 20 19:32:33 archlinux niri[7075]: 2025-05-21T02:32:33.845215Z DEBUG niri::backend::tty: this is the primary render node
May 20 19:32:33 archlinux niri[7075]: 2025-05-21T02:32:33.891089Z DEBUG niri::backend::tty: device changed: 57857
May 20 19:32:33 archlinux niri[7075]: 2025-05-21T02:32:33.892300Z DEBUG niri::backend::tty: new connector: DP-1 "Dell Inc. DELL U2723QE 16LLWN3"
May 20 19:32:33 archlinux niri[7075]: 2025-05-21T02:32:33.892314Z DEBUG niri::backend::tty: connecting connector: DP-1
May 20 19:32:33 archlinux niri[7075]: 2025-05-21T02:32:33.892325Z DEBUG niri::backend::tty: picking mode: Mode { name: "3840x2160", clock: 5332>
May 20 19:32:33 archlinux niri[7075]: 2025-05-21T02:32:33.892343Z DEBUG niri::backend::tty: set max bpc to 8
May 20 19:32:33 archlinux niri[7075]: 2025-05-21T02:32:33.895421Z DEBUG niri::niri: putting output DP-1 at x=0 y=0
May 20 19:32:33 archlinux niri[7075]: 2025-05-21T02:32:33.895452Z  INFO niri: listening on Wayland socket: wayland-1
May 20 19:32:33 archlinux niri[7075]: 2025-05-21T02:32:33.895455Z  INFO niri: IPC listening on: /run/user/1000/niri.wayland-1.7075.sock
May 20 19:32:33 archlinux systemd[6998]: Started A scrollable-tiling Wayland compositor.

● xwayland-satellite.service - Xwayland outside your Wayland
     Loaded: loaded (/usr/lib/systemd/user/xwayland-satellite.service; enabled; preset: enabled)
     Active: active (running) since Tue 2025-05-20 19:32:34 PDT; 2min 31s ago
 Invocation: 5545b0d3ca0e44688c5d05dd6bafaf7a
   Main PID: 7149 (xwayland-satell)
      Tasks: 13 (limit: 37176)
     Memory: 28.4M (peak: 30.2M)
        CPU: 61ms
     CGroup: /user.slice/user-1000.slice/[email protected]/app.slice/xwayland-satellite.service
             ├─7149 /usr/bin/xwayland-satellite
             └─7239 Xwayland -rootless -wm 8 -displayfd 9

May 20 19:32:34 archlinux xwayland-satellite[7149]:  2025-05-21T02:32:34.092Z INFO  xwayland_satellite         > Connected to Xwayland on :0
May 20 19:32:34 archlinux xwayland-satellite[7149]:  2025-05-21T02:32:34.092Z INFO  xwayland_satellite         > Successfully notified systemd of ready state.
May 20 19:32:34 archlinux systemd[6998]: Started Xwayland outside your Wayland.
May 20 19:32:34 archlinux xwayland-satellite[7149]:  2025-05-21T02:32:34.096Z INFO  xwayland_process           > The XKEYBOARD keymap compiler (xkbcomp) reports:
May 20 19:32:34 archlinux xwayland-satellite[7149]:  2025-05-21T02:32:34.096Z INFO  xwayland_process           > > Warning:          Unsupported maximum keycode 708, clipping.
May 20 19:32:34 archlinux xwayland-satellite[7149]:  2025-05-21T02:32:34.096Z INFO  xwayland_process           > >                   X11 cannot support keycodes above 255.
May 20 19:32:34 archlinux xwayland-satellite[7149]:  2025-05-21T02:32:34.097Z INFO  xwayland_process           > > Warning:          Could not resolve keysym XF86RefreshRateToggle
May 20 19:32:34 archlinux xwayland-satellite[7149]:  2025-05-21T02:32:34.097Z INFO  xwayland_process           > > Warning:          Could not resolve keysym XF86Accessibility
May 20 19:32:34 archlinux xwayland-satellite[7149]:  2025-05-21T02:32:34.097Z INFO  xwayland_process           > > Warning:          Could not resolve keysym XF86DoNotDisturb
May 20 19:32:34 archlinux xwayland-satellite[7149]:  2025-05-21T02:32:34.097Z INFO  xwayland_process           > Errors from xkbcomp are not fatal to the X server

It seems that xwayland-satellite is starting after Niri and it is connecting on :0. Could this be a bug with niri --session maybe?

Something to try would be replacing all the graphical-session.target in the service file with niri.service.

I tried this as well, to force xwayland-satellite to start after Niri instead of the graphical session :

ln -s /usr/lib/systemd/user/xwayland-satellite.service ~/.config/systemd/user/niri.service.wants/

FWIW I'm using tuigreet so there shouldn't be a conflicting DISPLAY I think.

[Supreeeme]

If you're setting DISPLAY in the niri config and it's not being set that might be some kind of niri issue. You may have more luck asking there.

[calebperkins]

Thanks for taking a look. I think I am running into the same problem as YaLTeR/niri#1625. It seems that stuff launched through systemd does not get the Niri config variables.

[calebperkins]

#169 and the latest changes in Niri solves my issue! Now XDG Autostart applications will play nice with Niri sessions and xwayland-satellite.