Re: Mesa vulkan layer path fix for core-updates

[John Kehayias]

Hi Kaelyn, Andreas, and Guix!

On Wed, Apr 19, 2023 at 04:07 PM, Kaelyn wrote:

> ------- Original Message -------
> On Wednesday, April 19th, 2023 at 3:26 PM, Andreas Enge <andreas@enge.fr> 
> wrote:
>
>>
>> Hello,
>>
>> thanks for bringing this back to our attention!
>
> You're welcome! :)

Yes, thanks Kaelyn, especially since I believe I said I wanted to help
these patches through for core-updates, before I had to step away for
a bit (all good now!).

>>
>> Am Wed, Apr 19, 2023 at 02:41:57PM +0000 schrieb Kaelyn:
>>
>> Given how many packages depend on mesa and their importance, I think it
>> would be safer to postpone the fix until after the merge; be it in a
>> dedicated mesa feature branch that could quickly be merged afterwards,
>> or better yet regroup other changes in this area. (Searching for open mesa
>> packages on issues.guix.gnu.org returns quite a few matches, this could be
>> a good occasion to sort them out.)
>
> I'm okay with it waiting until after the core-updates merge and going
> into a feature branch, especially if that branch includes updating
> mesa to the latest release (currently 23.0.0, or 22.3.7 if going with
> the latest patch of the previous feature release instead of the x.y.0
> release of the newest series).
>

I was going to suggest the same, a feature branch just after
core-updates is merged, including getting Mesa to the latest version
(I suspect a stable v23 will be here soon). I've used a newer Mesa
locally for some packages and I didn't hit any issues in the packaging
for v23.

I would be happy to team up with you to prepare this branch once it is
time. I see you did a good search below collecting the various related
issues/patches. I can take a look as well.

> Inspired by your comment, I also just did a quick scan of
> <https://issues.guix.gnu.org/search?query=mesa+is%3Aopen> and took a
> peek at some tickets that looked like they may be related to the mesa
> package. From that perspective, six other tickets caught my eye in the
> results:
>
> * <https://issues.guix.gnu.org/62176> can be closed when core-updates is
> merged, since core-updates contains mesa 22.2.4
>

Great, we'll be able to close it Real Soon Now.

> * <https://issues.guix.gnu.org/58887> looks like an alternate way of
> solving the layer path issues that <https://issues.guix.gnu.org/59453>
> also addresses. Additionally, it adds two new nonstandard VK_*_PATH
> variables to vulkan-loader, with at least VK_ILAYER_PATH seeming very
> similar in functionality to VK_LAYER_PATH and VK_ADD_LAYER_PATH
> described at
> <https://github.com/KhronosGroup/Vulkan-Loader/blob/main/docs/LoaderInterfaceArchitecture.md>
>

Thanks, will have a look at the differences.

> * <https://issues.guix.gnu.org/58251> would be fixed by 
> <https://issues.guix.gnu.org/59453>
>

Great, always good to close some issues :)

> * <https://issues.guix.gnu.org/62313> might need a modification to mesa
> e.g. to add VDPAU_DRIVER_PATH as a native-search-path (one possible
> solution; in my home profile I made VDPAU work by setting
> "VDPAU_DRIVER_PATH=/run/current-system/profile/lib/vdpau").
>

Right, this one is my report. I haven't had a chance to return to it
to figure out what is best here. Things do work with manual
intervention. It is a little tricky since my guess is we want VDPAU to
work without needing to install e.g. Mesa explicitly. But I don't
remember the details right now. Happy to discuss!

> * <https://issues.guix.gnu.org/48868> appears to be the same
> VDPAU_DRIVER_PATH issue as <https://issues.guix.gnu.org/62313>.
>

Yes, I think so too, though VLC does have Mesa as an input so the fix
might be easier directly for VLC at least.

> * Though not exactly mesa-related, <https://issues.guix.gnu.org/61364>
> can possibly be closed now, and almost certainly once the core-updates
> merge is completed. (The ticket is a number of workarounds the user
> applied in early Feb to be able to build their system profile using
> core-updates, to pick up Mesa 22 for newer hardware support. I'm not
> sure if any of the patches are still relevant.)
>

Also my quick reading of it; will double check none of those are still
out of date and we can close with core-updates.

> Cheers,
> Kaelyn

Thanks again Kaelyn! I think this will make for a small (but
non-trivial) set of patches for a feature branch and trying out that
workflow. We can then have the CI build the branch and people can try
their system with the newer Mesa plus fixes for testing. I don't think
there is any hardware support being dropped (unlike with v22) and it
will help for newer hardware, so I don't anticipate issues. But let me
not say that too loudly.

Looking forward to it!

John