This feature is useful for obtaining a backtrace from a Cplant compute node process that faults or terminates abnormally.
It is invoked by simply adding the bt option to the yod command line:
% yod -bt -sz 5 hello
When run this way, processes proceed to main() with an instance of gdb attached. The pct constantly monitors gdb's output and in the case that a process receives a signal, it requests a stack trace from gdb, which is relayed to yod and is displayed in yod's final summary of the job run.
To get the most information, it may be useful to recompile applications with debugging support. Typically one just adds the -g option to the compile line in the make file:
hello: hello.c
../bin/cc -g hello.c -o hello -lmpi
Cplant developers should also provide an alternate mpi library with debugging info called libmpi_debug.a - one would link to it using
hello: hello.c
../bin/cc -g hello.c -o hello -lmpi_debug