Re: "make run-qemu" gets Wayland protocol error

Demi Marie Obenour
2025-07-20T08:02:46Z

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On 7/20/25 03:55, Alyssa Ross wrote:
> Demi Marie Obenour <demiobenour@gmail.com> writes:
>
>> If I run `make run-qemu` under a Wayland compositor (tested with both
>> Sway and Weston), I get a Wayland protocol error ("invalid object 0")
>> and QEMU exits. It appears that there is a problem with
>> wayland-proxy-virtwl. I get the following error from foot:
>>
>> warn: main.c:437: 'C' is not a UTF-8 locale, falling back to 'C.UTF-8'
>> warn: config.c:3520: no configuration found, using defaults
>> Fontconfig warning: no <cachedir> elements found. Check configuration.
>> Fontconfig warning: adding <cachedir>/var/cache/fontconfig</cachedir>
>> Fontconfig warning: adding <cachedir prefix="xdg">fontconfig</cachedir>
>> err: wayland.c:1714: no compositor
>> err: wayland.c:2248: failed to flush wayland socket: Connection reset by peer
>>
>> And the following from wayland-proxy-virtwl:
>>
>> 2025-07-20 02:14:48.638 wl-proxy [WARNING]: Error handling client: Invalid_argument("invalid bounds in Cstruct.LE.get_uint32 [0,0](4096) off=0 len=4")
>
> This is partially fixed with <https://github.com/NixOS/nixpkgs/pull/419860>,
> which is more recent than Spectrum's pinned Nixpkgs. I expect to
> update that in the next few days, but until then, you can apply it on
> top of the Nixpkgs revision in lib/nixpkgs.default.nix, and then pass
> --arg config '{pkgsFun = import /path/to/nixpkgs;}' to any Spectrum
> Nix command.
>
> With that change, I'm able to run foot fine in QEMU. gnome-text-editor
> runs but prints errors and looks weird, and Firefox doesn't even start.
> crosvm built from the same tag as rutabaga_gfx used by QEMU works fine,
> so I think it must be a QEMU bug. I spent some time yesterday trying to
> debug it, but didn't get anywhere so far. If I can't figure it out soon
> I'll open an upstream bug report.

That's a good idea. Would it be possible to use vhost-user as a
workaround? That would use crosvm's implementation instead.

I'm glad that this isn't a TCG or wayland-proxy-virtwl bug,
unlike what I originally expected.
--
Sincerely,
Demi Marie Obenour (she/her/hers)

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