On the one hand recent versions of dev-libs/amdgpu-pro-opencl conflict with media-libs/mesa[opencl], on the other the former only satisfies virtual/opencl for ABI_X86=64. As a consequence, hilarity ensues if an ebuild depending on virtual/opencl also uses ABI_X86=32. amdgpu-pro-opencl has recently gained multilib support so it seems all it needs in order to allow updating virtual/opencl accordingly is being keyworded for ~x86.
Target keywords: ~amd64 ~x86
Just to clarify: this is still required. As I have just been made aware of, the ebuild in question was already keyworded ~x86. This was due to me having missed that change having been made in the PR implementing multilib support and was NOT in any way approved by anyone from the x86 arch team, therefore the invalid keyword has just been removed.
x86 keyworded, closing