
On my system I have XWayland disabled and therefore only WAYLAND_DISPLAY is set. This ensures that the graphical output will still be enabled on such setups (both Wayland and X11 are supported by the viewer).
*** NixOS *** NixOS is a Linux distribution based on the purely functional package management system Nix. More information can be found at https://nixos.org/nixos and in the manual in doc/manual.