I'm writing a parallel program using Open MPI. I'm running Snow Leopard 10.6.4, and I installed Open MPI through the homebrew package manager.
When I run my program using mpirun -np 8 ./test, every process reports that it has rank 0, and believes the total number of processes to be 1, and 8 lines of process rank: 0, total processes: 1 get spit out to the console.
I know it's not a code issue, since the exact same code will compile and run as expected on some Ubuntu machines in my college's computer lab. I've checked homebrew's bug tracker, and no-one's reported an issue with the Open MPI package. I'm at a loss.