kunfooses

I finally got Zoom screen sharing working on Wayland. Since many people have problems with Zoom screen sharing on Wayland, here are a few hints on what did the trick for me.

First, you need to install xdg-desktop-portal-wlr[1], which is an xdg-desktop-portal backend for wlroots[2]. Basically, you need this because Sway is based on wlroots and xdg-desktop-portal-wlr provides a ScreenCast interface to Zoom.

$ cat /nix/store/4z1a0hp99c6yga19jb46g50khnhrm0ql-xdg-desktop-portal-wlr-0.7.1/share/xdg-desktop-portal/portals/wlr.portal
[portal]
DBusName=org.freedesktop.impl.portal.desktop.wlr
Interfaces=org.freedesktop.impl.portal.Screenshot;org.freedesktop.impl.portal.ScreenCast;
UseIn=wlroots;sway;Wayfire;river;phosh;Hyprland;

Here is the relevant part of my NixOS configuration:

xdg.portal = {
  enable = true;
  xdgOpenUsePortal = true;
  wlr.enable = true;
  config = {
    common = {
      default = [ "wlr" ];
    };
    sway = {
      default = [ "wlr" ];
    };
  };
};

The config part creates the two files /etc/xdg/xdg-desktop-portal/portals.conf and /etc/xdg/xdg-desktop-portal/sway-portals.conf with the following identical content:

[preferred]
default=wlr

Now, you also get two systemd services, xdg-desktop-portal.service and xdg-desktop-portal-wlr.service. However, the xdg-desktop-portal-wlr.service unit failed to start with the error Portal service (wlroots implementation) was skipped because of an unmet condition check (ConditionEnvironment=WAYLAND_DISPLAY).. There is a race condition that starts the unit before the WAYLAND_DISPLAY variable is set and Sway hangs when I start it from the TTY via exec sway. I fixed this by adding the following lines to my ~/.config/sway/config:

exec systemctl --user import-environment WAYLAND_DISPLAY
exec systemctl --user restart xdg-desktop-portal-wlr.service

Hope this helps some of you to get Zoom screen sharing working with Sway.

[1] https://github.com/emersion/xdg-desktop-portal-wlr [2] https://gitlab.freedesktop.org/wlroots/wlroots