message: print error for incompatible HIP and CUDA settings
  Related issue:
diff: @@ -4,6 +4,11 @@ if (NOT CMAKE_BUILD_TYPE STREQUAL "Release")
  "will be affected")
  endif()
  +if (GINKGO_BUILD_CUDA AND GINKGO_BUILD_HIP AND GINKGO_HIP_PLATFORM MATCHES "hcc")
  + message(FATAL_ERROR "Building the benchmarks with both HIP AMD and CUDA support "
  + "at the same time is currently not supported. Use `export HIP_PLATFORM=nvcc` instead.")
  +endif()
  +
  function(ginkgo_benchmark_cusp_linops name)
  target_compile_definitions("${name}" PRIVATE HAS_CUDA=1)
  target_link_libraries("${name}" ginkgo ${CUDA_RUNTIME_LIBS}
  