[mpich-discuss] working on a process using gdb

[Calin Iaru]

I notice that "show env" command when starting mpiexec -gdb reports some 
false values; for instance, the HOSTNAME is set always to one machine, 
instead of the machines that are running the processes. On the other hand, 
MPD_JRANK varies as it should. This scenario occurs with Linux and mpd as 
process manager.

I am interested when debugging to execute some debugging commands only on 
one process. For instance, printing the stack iterator is done like this:

0,3-8,10:  (gdb) print i
0:  $2 = 3
3-8:  $2 = 0
0,3-8:  (gdb) 10:  $2 = 2

Is there a way to specify the process on which I would like to run the 
command?