Segfault for custom xkb keymap

[JerwuQu]

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

Launching a gamescope instance with a xkb system keymap and pressing any key causes a segfault crash.

In my case, the keymap is in ~/.xkb/symbols and xkbcli compile-keymap --layout <mykeymap> works fine. It seems to rather be an issue with the binary caps and libxkbcommon not having access to that directory in that context.

Steps To Reproduce

To reproduce, you don't even need to have created a custom keymap, you can simply run:

XKB_DEFAULT_LAYOUT=nonexistentlayout gamescope -- glxgears

and hit a key.

Hardware information

- Distro: Arch
- CPU: AMD Ryzen 9 3900X
- GPU: Radeon RX 9070 XT
- Driver Version: Mesa 25.3.2-arch1.1

Software information

- Desktop environment: hyprland
- Session type: wayland
- Gamescope version: 3.16.19 (gcc 15.2.1)
- Gamescope launch command(s): see reproduction info

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

I would expect gamescope to fall back to another keymap or exiting with an error rather than segfault.

Workaround: Move keymap to system dir, change caps, or use a system available keymap.

[JerwuQu]

Related: #203