I'm not sure how should I interpret this message:
[local:17344] *** An error occurred in MPI_Testsome
[local:17344] *** on communicator MPI COMMUNICATOR 5 CREATE FROM 0
[local:17344] *** MPI_ERR_TRUNCATE: message truncated
[local:17344] *** MPI_ERRORS_ARE_FATAL (goodbye)
mpiexec noticed that job rank 0 with PID 17338 on node local exited
on signal 15 (Terminated).
3 additional processes aborted (not shown)
I am assuming that the error was triggered because one of the buffers
I set in the MPI_Recv_init() calls can not contain the incoming
message. However, I don't understand why job rank 0 terminates first.
The only process that contains a call to MPI_Testsome has actually
rank 3, and it's receiving messages from rank 0.
Also I think it would be a good idea to print the message tag in the
error log.