Hereby I have a master-worker model, where the one and only master start a MPI_Comm workercomm and all the workers are spawned by MPI_Comm_spawn in it. Of course in the first run some bugs exists and debug tools are needed.

So to gdb master isn’t hard, yet if I want to debug worker it’s another story. MPICH guide
FAQ:
Debugging applications in parallel tells me gdb CAN be used with MPI, yet if it is spawned by another process, I have to make a infinite loop and wait gdb to attach to it, where I have to do this 10+ times each run. Yet all I have is gdb, and those parallel debuggers aren’t available to me. Is there anything that makes this less painful?