In case several OpenCL implementations sharing devel/LLVM > LLVM 3.X are installed, software compiled with the OpenCL backend will fail with an error like:
Device open failed, aborting...
: CommandLine Error: Option 'enable-value-profiling' registered more than once!
LLVM ERROR: inconsistency in registered CommandLine options
Nothing to output !
(the error message above has been taken from clinfo, see Bug 231226).
This problem seems to be unresolved in LLVM, although known since a couple of years for now. See, for instance, Bug 219562, Bug 224584 where I tried to gather some of the bug reports on LLVM.
In case devel/ocl-icd is installed, graphics/blender seem to fail when compiled using OpenCL and option CYCLES - calling blender results in the same error as shown above.
To reproduce the error described here, try to have installed mesa,beignet as well as devel/clinfo and devel/ocl-icd and/or lang/pocl.
devel/clinfo reveals the problem quickly.
lang/pocl is useless if used with an ICD.
Can someone help on this?
*** This bug has been marked as a duplicate of bug 233495 ***