Hi I think I’ve done something stupid when installing mpich, so thanks in advance for your patience. The following is a minimal working example of the bug: #include <stdio.h> #include <mpi.h> int main(int argc, char** argv) { MPI_Init(NULL, NULL); printf("Before barrier\n"); MPI_Barrier(MPI_COMM_WORLD); printf("After barrier\n"); MPI_Finalize(); } I compile it with the command mpicc -o minimal_working_example minimal_working_example.c When I run it with the commandmpiexec -n 1 ./minimal_working_example I get the output Before barrier After barrier which is what I expect. When I run it with the command mpiexec -n 2 ./minimal_working_example I get the output Before barrier Before barrier =================================================================================== = BAD TERMINATION OF ONE OF YOUR APPLICATION PROCESSES = PID 45072 RUNNING AT localhost = EXIT CODE: 11 = CLEANING UP REMAINING PROCESSES = YOU CAN IGNORE THE BELOW CLEANUP MESSAGES =================================================================================== YOUR APPLICATION TERMINATED WITH THE EXIT STRING: Segmentation fault: 11 (signal 11) This typically refers to a problem with your application. Please see the FAQ page for debugging suggestions which is not what I expect. For the record the same occurs when running the `comare_bcast` program found at, https://github.com/wesleykendall/mpitutorial/tree/gh-pages/tutorials/mpi-bro... <https://github.com/wesleykendall/mpitutorial/tree/gh-pages/tutorials/mpi-broadcast-and-collective-communication/code>. Since I really expected this code to work I suspect that I’ve installed mpich incorrectly. I’m on OSX 10.11.4 and installed mpich using the command sudo port install mpich Any advice welcome. Thank you very much for your help. Ben _______________________________________________ discuss mailing list [email protected] To manage subscription options or unsubscribe: https://lists.mpich.org/mailman/listinfo/discuss