Bug#986970: qgis: QGIS cannot detect installed OpenCL drivers unless `ocl-icd-opencl-dev` package is installed

Pedro Ângelo

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Apr 14, 2021, 2:10:03 PM4/14/21

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Package: qgis
Version: 3.10.14+dfsg-1
Severity: normal

Dear Maintainer,

I tried to enable OpenCL acceleration on QGIS options menu by going to
"Settings -> Options -> Acceleration" and toggling the "Enable OpenCL
Acceleration" menu option.

At first, this failed with a message that it could not find the appropriate
drivers. After installing the `mesa-opencl-icd` package, which enabled OpenCL
for my GPU in other applications, QGIS still failed to detect the drivers.

After some digging, I found that QGIS was trying to dlopen `libOpenCL.so` in
several locations, but the `ocl-icd-libopencl1` package installed by `mesa-
opencl-icd` only provided `libOpenCL.so.1`.

Symlinking `libOpenCL.so.1` to `libOpenCL.so` fixes the issue, and this is
provided by the `ocl-icd-opencl-dev` package.

I suggest that this package is either added to the QGIS package suggestions or
the error message within QGIS is updated to suggest installing it.

Best regards,

P.

-- System Information:
Debian Release: bullseye/sid
APT prefers testing-security
APT policy: (500, 'testing-security'), (500, 'testing')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 5.10.0-5-amd64 (SMP w/8 CPU threads)
Kernel taint flags: TAINT_WARN
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8),
LANGUAGE=en_GB:en
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages qgis depends on:
ii libc6 2.31-11
ii libgcc-s1 10.2.1-6
ii libgdal28 3.2.1+dfsg-1+b1
ii libgeos-c1v5 3.9.0-1
ii libgsl25 2.6+dfsg-2
ii libqgis-analysis3.10.14 3.10.14+dfsg-1
ii libqgis-app3.10.14 3.10.14+dfsg-1
ii libqgis-core3.10.14 3.10.14+dfsg-1
ii libqgis-gui3.10.14 3.10.14+dfsg-1
ii libqt5core5a 5.15.2+dfsg-5
ii libqt5gui5 5.15.2+dfsg-5
ii libqt5keychain1 0.10.0-1
ii libqt5network5 5.15.2+dfsg-5
ii libqt5sql5 5.15.2+dfsg-5
ii libqt5webkit5 5.212.0~alpha4-11
ii libqt5widgets5 5.15.2+dfsg-5
ii libqt5xml5 5.15.2+dfsg-5
ii libstdc++6 10.2.1-6
ii ocl-icd-libopencl1 [libopencl1] 2.2.14-2
ii python3-qgis 3.10.14+dfsg-1
ii qgis-common 3.10.14+dfsg-1
ii qgis-providers 3.10.14+dfsg-1
ii qt5-image-formats-plugins 5.15.2-2

Versions of packages qgis recommends:
ii qgis-plugin-grass 3.10.14+dfsg-1

Versions of packages qgis suggests:
pn gpsbabel <none>

Pedro Ângelo

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Apr 14, 2021, 3:50:04 PM4/14/21

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On Wed, 2021-04-14 at 20:44 +0200, Sebastiaan Couwenberg wrote:

[...]

> Adding a runtime dependency on a -dev package is not appropriate.
>
> libqgis-analysis & libqgis-app have libOpenCL.so.1 in their NEEDED
> section so it seems to be properly linked in version 3.16.x
>
> QGIS 3.10.x is EOL so don't expect this issue to get fixed upstream. Use
> qgis from experimental instead.
>
> Kind Regards,
>
> Bas
>

Sure, but isn't 3.10 the version going into next stable, or will 3.16 migrate
before release?

If it isn't, then for the next couple of years, QGIS users on Debian stable with
working OpenCL setups will try to click that button and be confused. If it's too
late to patch the error message, installing `ocl-icd-opencl-dev` as a workaround
should at least be mentioned in the README.

Best regards,
P.

Sebastiaan Couwenberg

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Apr 15, 2021, 12:10:03 AM4/15/21

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On 4/14/21 9:36 PM, Pedro Ângelo wrote:
> Sure, but isn't 3.10 the version going into next stable, or will 3.16 migrate
> before release?

See:

https://lists.debian.org/debian-gis/2021/02/msg00001.html

Kind Regards,

Bas

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