When `exo-open` launches a preferred application from inside a Wayland session, it sets `$DISPLAY` to `$WAYLAND_DISPLAY`, which breaks programs that don't support Wayland. To demonstrate: ```sh echo $DISPLAY exo-open --launch TerminalEmulator # echo $DISPLAY in new TerminalEmulator window ``` On my system `echo $DISPLAY` prints `:0` before `exo-open` and `wayland-1` in the new TerminalEmulator window. This occurs due to the [`set_environment`](https://gitlab.xfce.org/xfce/exo/-/blob/xfce-4.16/exo/exo-execute.c#L91) function [passed to `g_spawn_async` by `exo_execute_preferred_application_on_screen`](https://gitlab.xfce.org/xfce/exo/-/blob/xfce-4.16/exo/exo-execute.c#L289-300) which sets `$DISPLAY` to the result of `gdk_display_get_name`.