Dzmitry,
specifying MSMPI_PRINT_ENVIRONMENT_BLOCK in the command line will work with the executable built with msmpi. In case it is just any executable (whoami, etc), the environment block will not be printed.
PID is not a part of output for MSMPI_PRINT_ENVIRONMENT_BLOCK. smpd process outputs PIDs as part of its debug output, but it is only being printed out as part of the shutdown sequence.
mpiexec -d 3 -n 2 hostname
...
[01:45308] process_id=0 rank=1 refcount=0, waiting for the process to finish exiting.
[01:45308] creating an exit command for process id=0 rank=1, pid=29584, exit code=0.
[01:45308] posting command SMPD_EXIT to parent, src=1, dest=0.
[01:45308] Handling cmd=SMPD_STDOUT result
...
-thanks, Anna