GDB
From HCL
Debugging with GDB
compile programme with -g -o0 (or ./configure --enable-debug)
For serial programme (or MPI running with 1 process)
gdb ./programme_name
To debug MPI application in parallel add this line to somewhere in the code:
if (!rank) getc(stdin); MPI_Barrier(MPI_COMM_WORLD);
Then run the code and it will hang on that line.