When using a newer Clang as CUDA compiler for Kokkos (newer than supported by CUDA), the current Legion CMake fails during CUDA Compiler Detection. The only workaround right now seems to be passing -DCMAKE_CUDA_FLAGS="--allow-unsupported-compiler -std=c++17" to Legion.
Example: Clang 17.0.6 and CUDA 11.7.1
Setting -DCMAKE_CUDA_FLAGS="--allow-unsupported-compiler" but without the -std=c++17 you get more errors.
Setting CMAKE_CUDA_STANDARD has no effect.
The errors seem to originate in find_package(Kokkos), prior to the Legion CMake logic in legion that tries to set the C++ standard for CUDA. It might require moving that logic before find_package(Kokkos).
Issue mentioned in https://github.com/spack/spack/pull/45036
When using a newer Clang as CUDA compiler for Kokkos (newer than supported by CUDA), the current Legion CMake fails during CUDA Compiler Detection. The only workaround right now seems to be passing
-DCMAKE_CUDA_FLAGS="--allow-unsupported-compiler -std=c++17"to Legion.Example: Clang 17.0.6 and CUDA 11.7.1
Setting
-DCMAKE_CUDA_FLAGS="--allow-unsupported-compiler"but without the-std=c++17you get more errors.Setting
CMAKE_CUDA_STANDARDhas no effect.The errors seem to originate in
find_package(Kokkos), prior to the Legion CMake logic in legion that tries to set the C++ standard for CUDA. It might require moving that logic beforefind_package(Kokkos).