Black screen in XR on linux when using compatibility renderer

[DanielKinsman]

Tested versions

Reproducible in 4.2.2, 97b8ad1

System information

Godot v4.2.2.stable unknown - Arch Linux #1 SMP PREEMPT_DYNAMIC Fri, 12 Jul 2024 00:06:53 +0000 - Wayland - GLES3 (Compatibility) - AMD Radeon RX 6800 XT (radeonsi, navi21, LLVM 18.1.8, DRM 3.57, 6.9.9-arch1-1) () - AMD Ryzen 7 5800X3D 8-Core Processor (16 Threads)

Issue description

When using the compat renderer in XR only blackness is presented in the headset and the desktop window. The mobile renderer works correctly.

Verbose output: glcompatpico4blackscreen.log

glxinfo.txt including mesa version etc.

Setup in case it helps:

• arch linux up to date as of 2024-07-17
• alvr v20.9.1
• steamvr v2.6.2
• pico 4 headset running the alvr app (though I suspect it would be the same on quest as it is ALVR running the show)

Apologies if this ends up being a mesa, alvr or steamvr bug instead. I suspect it has only started occurring recently but I can't remember if I was using the compat renderer 6 months ago or not.

Steps to reproduce

1. Get ALVR and steamvr set up and running on linux (edit: you do not need a headset to do this).
2. Launch an xr project that uses the compatibility renderer

I've attached a min repo project below but the same behaviour occurs for all godot projects, including these: https://itch.io/jam/godot-xr-game-jam-july-2024/entries. Except for the dog one, because I made that using the mobile renderer.

Minimal reproduction project (MRP)

glcompattest2.tar.gz

[DanielKinsman]

I should note that you do not need a VR headset to replicate this, simply installing and starting ALVR and SteamVR is enough.

[DanielKinsman]

Pretty sure this is because mesa lacks GL_OVR_multiview/GL_OVR_multiview2 extension support.

https://gitlab.freedesktop.org/mesa/mesa/-/issues/10712

Similar to #85422 but with a different vendor and the gl extension not the webxr extension. I hear vision os also doesn't support the webxr extension?