`--expose-wayland` breaks `--mangoapp`

[gmankab]

Is there an existing issue for this?

• I have searched the existing issues

Are you using any gamescope patches or a forked version of gamescope?

• The issue occurs on upstream gamescope without any modifications

Current Behavior

mangohud is not visible on screen, see log below

Steps To Reproduce

run gamescope using launch command listed below

Hardware information

- Distro: fedora 44
- CPU: Intel(R) Xeon(R) E5-2670 v3 (24) @ 3.10 GHz
- GPU: AMD Radeon RX 6800
- Driver Version: Mesa 26.1.5

Software information

- Desktop environment: niri
- Session type: wayland
- Gamescope version: 

> gamescope --version
[gamescope] [Info]  console: gamescope version  (gcc 16.1.1)
> rpm -q gamescope
gamescope-3.16.25-1.fc44.x86_64

- Gamescope launch command(s): `gamescope --backend=wayland --expose-wayland --steam --mangoapp -- steam`

Which gamescope backends have the issue you are reporting?

• Wayland (default for nested gamescope)
• DRM (default for embedded gamescope, i.e. gamescope-session)
• SDL
• OpenVR

Logging, screenshots, or anything else

Glfw Error 65550: X11: Platform not initialized
[gamescopereaper] reaper: "mangoapp" process shut down. Restarting.

[gmankab]

workaround is a wrapper script that unsets WAYLAND_DISPLAY variable for mangoapp

#!/bin/sh
unset WAYLAND_DISPLAY
exec /usr/bin/mangoapp "$@"