When you run MPI on nodes without GPUs (e.g., general-purpose CPU nodes) after loading the Base/GCC module, CUDA-related warning messages may appear. These warnings do not affect job execution, but if you want to suppress them, please specify the following option when executing mpirun:

--mca opal_warn_on_missing_libcuda 0

In addition, the warning can also be resolved by loading the CUDA module after the Base/GCC modules as shown below. However, since CUDA cannot actually be used on CPU nodes and multiple related paths would be set, we recommend addressing this issue using the method described above (specifying options at the time of mpirun execution).

$module load cuda/11.8

Reference page: OpenMPI Usage Method (SQUID General-Purpose CPU Node)