[mod3 (modulepath)]$ module purge
[mod3 (modulepath)]$ module load pgi/19.4
[mod3 (modulepath)]$ module load openmpi/4.0
[mod3 (modulepath)]$ module list
Currently Loaded Modulefiles:
  1) pgi/19.4      2) openmpi/4.0
[mod3 (modulepath)]$ mpirun
mpirun (openmpi/4.0, pgi/19.4)
[mod3 (modulepath)]$ module unload openmpi
[mod3 (modulepath)]$ module switch pgi intel/2019
[mod3 (modulepath)]$ module load openmpi/4.0
[mod3 (modulepath)]$ module list
Currently Loaded Modulefiles:
  1) intel/2019    2) openmpi/4.0
[mod3 (modulepath)]$ mpirun
mpirun (openmpi/4.0, intel/2019)
[mod3 (modulepath)]$ module unload openmpi
[mod3 (modulepath)]$ module switch intel gcc/9.1.0
[mod3 (modulepath)]$ module load openmpi/4.0
[mod3 (modulepath)]$ mpirun
mpirun (openmpi/4.0, gcc/9.1.0)
[mod3 (modulepath)]$ module unload openmpi
[mod3 (modulepath)]$ module switch gcc gcc/8.2.0
[mod3 (modulepath)]$ module load openmpi/4.0
ModuleCmd_Load.c(213):ERROR:105: Unable to locate a modulefile for 'openmpi/4.0'
[mod3 (modulepath)]$ module list
Currently Loaded Modulefiles:
  1) gcc/8.2.0
