It is often convenient to have a debugger start when a program detects an
error. If mpich was configured with the option --enable-mpedbg, then
adding the command-line option -mpedbg to the program will cause
mpich to attempt to start a debugger (usually dbx or gdb) when
an error that generates a signal (such as SIGSEGV) occurs. For
example,
mpirun -np 4 a.out -mpedbgIf you are not sure if your mpich provides this service, you can use -mpiversion to see if mpich was built with the --enable-mpedbg option.