parallel_env needs to be set and it is not in default experiment.wrf4g files.

[markelg]

parallel_env = "MPIRUN" needs to be added to experiment.wrf4g in order to WRF to work, if parallel_wrf is set to true. Otherwise is fails with the following error.

2022-08-01 13:30:49,476 Run wrf
2022-08-01 13:30:49,559 Unexpected error:
Traceback (most recent call last):
  File "/home/users/garciam/.drm4g/jobs/.gw_garciam_21/lib/python/wrf4g/wrapper.py", line 544, in launch
    self.main_workflow()
  File "/home/users/garciam/.drm4g/jobs/.gw_garciam_21/lib/python/wrf4g/wrapper.py", line 589, in main_workflow
    self.run_wrf(binaries)
  File "/home/users/garciam/.drm4g/jobs/.gw_garciam_21/lib/python/wrf4g/wrapper.py", line 1317, in run_wrf
    cmd = "%s wrf_launcher.sh %s" % (params.parallel_run, wrf_exe)
AttributeError: 'PilotParams' object has no attribute 'parallel_run'
2022-08-01 13:30:49,559 'PilotParams' object has no attribute 'parallel_run'

In the documentation it says that MPIRUN is the default value, but it is not, right now it needs to be explicitly set. This is a problem in the logic of wrapper.py.