CMake Error (missing OpenMP_CUDA_FLAGS) on Windows when building with CUDA

User discussions
1

GROMACS version: 2025.0
GROMACS modification: No

I’m trying to build GROMACS with CUDA support on Windows, using MSVC toolchain.

I have the latest CMake (3.31.5) installed.
I’ve setup CUDA 12.4.1, and I have Visual Studio 2022.
(in fact I’am using GitHub Actions Windows Runner, see this for more detail about installed packages)

The cmake command is

cmake .. "-DCMAKE_INSTALL_PREFIX=C:/GROMACS2025" "-DCMAKE_PREFIX_PATH=C:/FFTW;C:/OpenBLAS" "-DGMX_SIMD=AVX2_256" "-DGMX_GPU=CUDA" "-DGMX_HWLOC=ON" -G "Visual Studio 17 2022" -A "x64"

And it gave the following error message:

-- Performing Test HAVE_NO_DEPRECATED_COPY
-- Performing Test HAVE_NO_DEPRECATED_COPY - Failed
-- Performing Test HAS_WARNING_EVERYTHING
-- Performing Test HAS_WARNING_EVERYTHING - Failed
CMake Error at C:/Program Files/CMake/share/cmake-3.31/Modules/FindPackageHandleStandardArgs.cmake:233 (message):
  Could NOT find OpenMP_CUDA (missing: OpenMP_CUDA_FLAGS
  OpenMP_CUDA_LIB_NAMES)
Call Stack (most recent call first):
  C:/Program Files/CMake/share/cmake-3.31/Modules/FindPackageHandleStandardArgs.cmake:603 (_FPHSA_FAILURE_MESSAGE)
  C:/Program Files/CMake/share/cmake-3.31/Modules/FindOpenMP.cmake:616 (find_package_handle_standard_args)
  src/external/muparser/CMakeLists.txt:28 (find_package)


-- Configuring incomplete, errors occurred!

I’ve googled these, but find nothing about OpenMP_CUDA_FLAGS and OpenMP_CUDA_LIB_NAMES.

I’ve re-installed old cmake (like 3.30.7), the cmake command runs well (despite an error occurred during the subsequent compiling, but that error was not related to the problem in this post, so that error was discussed in a new post.).
Installing old version of cmake might be a work-around, but it is not a solution – new version of cmake will take place of old version eventually. So, I think this problem need a fix.

2

The error message you are encountering during the CMake configuration process indicates that the build system is unable to find the necessary OpenMP support for CUDA

3

Since cmake 3.30 works but cmake 3.31 doesn’t work, I think there must be some change between cmake 3.30 and 3.31.

For build system compatibility in future, I think the cmake files need improvements.