Mesa OpenCL sometimes failing leading to OpenCL deactivation

Is there an existing issue for this?

• I checked and did not find my issue in the already reported ones

Describe the bug

When starting darktable with OpenCL activated using the rusticl driver this sometimes fails and OpenCL get's deactivated

Steps to reproduce

There is no defined reproducer.

Expected behavior

Not fail :-)

Logfile | Screenshot | Screencast

This is what i see on log console

MESA-LOADER: failed to retrieve device information
failed to get driver name for fd 18

instead of the "usual"

=== Rusticl warning: Patched Mesa libclc not detected. Upstream libclc may contain known bugs or breaking changes and isn't guaranteed to work reliably. Please visit https://gitlab.freedesktop.org/karolherbst/mesa-libclc for more information. ===

After darktable OpenCL was deactivated when seing this error, i can activate it again via the preferences and restart darktable, everything is good.

Commit

No response

Where did you obtain darktable from?

self compiled

darktable version

master

What OS are you using?

Linux

What is the version of your OS?

Current Fedora, Mesa 26.2.2

Describe your system

AMD Strix Halo

Are you using OpenCL GPU in darktable?

Yes

If yes, what is the GPU card and driver?

StrixHalo, rusticl

Please provide additional context if applicable. You can attach files too, but might need to rename to .txt or .zip

No response

No source file, test, or defined reproducer is named. Start by running self-compiled darktable master on Fedora with OpenCL enabled through the rusticl driver, compare the reported Mesa loader and Rusticl logs across startups, and trace the OpenCL activation and deactivation behavior. Done means the intermittent failure is reproducible and its handling is addressed or clearly diagnosed.