WEBKIT_DISABLE_COMPOSITING_MODE=1 is necessary to make WebkitGtk based app render properly

[ImBearChild]

Qubes OS release

Qubes Release 4.2.3 (R4.2)

Brief summary

WebKitGTK based application will use Accelerated Compositing mode to render web content. However, this feature does not behave properly under software provided OpenGL (llvmpipe).¹ Using WEBKIT_DISABLE_COMPOSITING_MODE=1 to disable this mode. ² Maybe Qubes can add WEBKIT_DISABLE_COMPOSITING_MODE=1 to user's default environment.

Steps to reproduce

1. Install a WebKitGtk based application (Epiphany, Remmina Web, Tauri ...)
2. Open a webpage in it.
3. See this bug. Black secreen or nothing will be displayed. And the app may output following message in stdout.

   Failed to get GBM device
   Failed to get GBM device
   

Expected behavior

Behave properly.

Actual behavior

Not behave properly.

Footnotes

1. This bug effects many user, not only software render users. For example: https://github.com/NixOS/nixpkgs/issues/32580 ↩

2. https://trac.webkit.org/wiki/EnvironmentVariables ↩