This is hardcoded to 120 (= OpenCL 1.2) because nvidia does not support later standards until 3.0 comes around and we do not make use of later features anyway. The warning looks like this by the way:
In file included from /usr/include/CL/cl.h:32,
from ../ufo/ufo-processor.c:25:
/usr/include/CL/cl_version.h:34:9: note: #pragma message: cl_version.h: CL_TARGET_OPENCL_VERSION is not defined. Defaulting to 220 (OpenCL 2.2)
34 | #pragma message("cl_version.h: CL_TARGET_OPENCL_VERSION is not defined. Defaulting to 220 (OpenCL 2.2)")
| ^~~~~~~
This is hardcoded to 120 (= OpenCL 1.2) because nvidia does not support later standards until 3.0 comes around and we do not make use of later features anyway. The warning looks like this by the way: