Wezterm WebGpu doesn't work with llvmpipe driver

[DUOLabs333]

What Operating System(s) are you seeing this problem on?

Linux X11

Which Wayland compositor or X11 Window manager(s) are you using?

KWin

WezTerm version

20240203-110809-5046fc22

Did you try the latest nightly build to see if the issue is better (or worse!) than your current version?

No, and I'll explain why below

Describe the bug

I didn't try the nightly build as it isn't available for ARM.

If I install vulkan-swarst and try to run wezterm --config 'front_end="WebGpu"', it fails with the message

Failed to create window: Limit 'max_compute_workgroups_per_dimension' value 65535 is better than allowed 0

This is the same message that runs if I uninstall swrast, which implies that wezterm isn't picking up the driver. However, this is unique to the swrast/wezterm combination --- vulkaninfo or vkcube works as expected, and pointing wezterm to a different driver works.

To Reproduce

1. Uninstall every vulkan driver
2. Install vulkan-swrast
3. Run wezterm --config 'front_end="WebGpu"'
4. See issue.

Configuration

front_end="WebGpu"

Expected Behavior

For wezterm to work as expected.

This did not happen before, so I think it's a regression in either swrast or wezterm.

Logs

No response

Anything else?

No response

[RoninTech]

I'm using wezterm on an RPi5 and get nightly builds built for Arm64 (Debian12). Just in case it might work for you the instructions are here:

https://wezfurlong.org/wezterm/install/linux.html

Unfortunately I'm finding recent wezterm arm64 builds are unusable now as the video in my PR describes.

[DUOLabs333]

Oh, I was only looking at the "raw" builds (I'm on Arch). I'll extract a deb and try it out.