Hi, Guosheng,
The kernel_generator is a small executable
Code:
ngsolve_build/ngsolve/basiclinalg/kernel_generator
So it seems that this executable links against the MPI library but cannot find it when it is executed.
You can "ldd" the executable to confirm this, you should get a line like:
Code:
libmpi.so.12 => not found
Maybe the path to your MPI library is not in your LD_LIBRARY_PATH?
You could try to put the MPI library into LD_PRELOAD for the build. That should force it to load.
Best,
Lukas