X11 backend doesn’t work in a VM with no GPU

[DemiMarie]

Describe the bug
If the X server doesn’t support the DRI3 extension, the X11 backend doesn’t work.

To Reproduce
Start Wayfire in an X11 session with no access to a GPU. This is uncommon on bare hardware, but quite common in VMs.

I hit this when trying to use Wayfire in Qubes OS to see if the current custom Xorg driver could be replaced by a custom Wayfire plugin, but this error shouldn’t be Qubes OS-specific.

Expected behavior
Works using llvmpipe.

Screenshots or stacktrace
N/A. The exact error is:

Failed to get DRM file descriptor, try specifying a valid WLR_RENDER_DRM_DEVICE!

Wayfire version
Fedora 40 RPM package from the default repository.

[soreau]

There are open merge requests for wlroots and mesa. You left comments, but it's been awhile, and they're still open. That said, I don't really think this is a wayfire issue. You can have a look at the pixman backend in wayfire for bookworm, if you want to try using it or porting it to latest wayfire.