Problems when you start an MPI program

You encounter problems when you start an MPI program.

Solution

Check whether you can run a single-process (non-MPI) program such as a trivial Hello, World! program, resolve any issues that arise, and repeat the attempt to run a multi-process job. Use any issues that you encounter as the starting point for diagnosing the problem.
Verify that MPI is working correctly by running a job without any of Linaro Forge products applied, such as the example in the examples directory of the installation.
```
mpirun -np 8 ./a.out
```
Verify that mpirun is in the PATH, or the environment variable

FORGE_MPIRUN is set to the full pathname of mpirun.