Problem with OpenCL in darktable with AMD Card

Hello Everybody!

I can’t get OpenCL to work with Darktable and unfortunately I don’t know a lot about that stuff, that’s why I’m looking for help.

I have a Lenovo x230 running Debian 10 and an external GPU via Expresscard. GPU is an AMD RX460. The GPU is working, but the Terminal tells me this:

flatpak run org.darktable.Darktable -d opencl
0.135735 [opencl_init] opencl related configuration options:
0.135753 [opencl_init] 
0.135756 [opencl_init] opencl: 1
0.135759 [opencl_init] opencl_library: ''
0.135763 [opencl_init] opencl_memory_requirement: 768
0.135766 [opencl_init] opencl_memory_headroom: 300
0.135769 [opencl_init] opencl_device_priority: '*/!0,*/*/*'
0.135772 [opencl_init] opencl_mandatory_timeout: 200
0.135775 [opencl_init] opencl_size_roundup: 16
0.135778 [opencl_init] opencl_async_pixelpipe: 0
0.135782 [opencl_init] opencl_synch_cache: 0
0.135788 [opencl_init] opencl_number_event_handles: 25
0.135796 [opencl_init] opencl_micro_nap: 1000
0.135802 [opencl_init] opencl_use_pinned_memory: 0
0.135807 [opencl_init] opencl_use_cpu_devices: 0
0.135813 [opencl_init] opencl_avoid_atomics: 0
0.135819 [opencl_init] 
0.135952 [opencl_init] could not find opencl runtime library 'libOpenCL'
0.136001 [opencl_init] could not find opencl runtime library ''
0.137863 [opencl_init] found opencl runtime library ''
0.137886 [opencl_init] opencl library '' found on your system and loaded
0.496281 [opencl_init] found 1 platform
0.496321 [opencl_init] found 1 device
0.496660 [opencl_init] discarding device 0 `AMD Radeon (TM) RX 460 Graphics (POLARIS11, DRM 3.33.0, 4.19.0-6-amd64, LLVM 7.0.1)' due to missing image support.
0.496678 [opencl_init] no suitable devices found.
0.496690 [opencl_init] FINALLY: opencl is NOT AVAILABLE on this system.
0.496703 [opencl_init] initial status of opencl enabled flag is OFF.

I did install and uninstall a lot of stuff, and I’m a bit lost now…
I installed Opencl from the AMD website with:
./amdgpu-pro-install --opencl=legacy,pal --headless
And I think I got both drivers installed, the open and the closed one.

And help would be highly appreciated!
Thanks in advance!

The required image support is not on your driver. No luck.