A wrapper arround mpiexec, gdbserver, and gdb that makes debugging MPI programs eaiser with a moderate number of processes.
This wrapper defines several GDB extension commands that should help make things easier too.
mpic continue, but all processes
mpict continue this thread, and switch to the next one that is stopped if there is one
mpip print on all or a subset of threads using -t $tid
mpib break on all or a subset of threads using -t $tid
You also should probably know about the following buildin commands
thread apply all applies a command to all threads
continue & in GDB any command ending in & runs a command "in the background" allowing the user to continue to interact with GDB. In this case continue this thread in the background
info threads get a list of threads and their status
interupt if the current thread is running stop it.
thread $tid switch to thread id
Dependencies:
gdb 12.1 or later with gdbserver which is sometimes packaged seperately and python support which may be disabled if compiled from sourcempiexecEarlier versions may work, but are not tested
gdbserver supports running the debugger and gdb on seperate nodes, but this command currently does not (PRs welcome).
For HPC systems with meaningful scale, we should probably integrate with PMIx, but we currently do onot.
Sometimes the program failes to successfully launch and connect to the server. This is often resolved by restarting.