Openstack tripleo validator show run results in KeyError: 'tasks' in validator show

Issue

When running the validation 'show run' subcommand fails with an exception KeyError: 'tasks'. This issue affects only the failed validations.

(undercloud) [stack@undercloud-0 ~]$ openstack tripleo validator show run ca8cf026-c9c6-43e1-92e6-3795e7b2f6a3
 Exception occured while running the command
 Traceback (most recent call last):
   File "/usr/lib/python3.6/site-packages/tripleoclient/command.py", line 32, in
 run
     super(Command, self).run(parsed_args)
   File "/usr/lib/python3.6/site-packages/osc_lib/command/command.py", line 41,
 in run
     return super(Command, self).run(parsed_args)
   File "/usr/lib/python3.6/site-packages/cliff/command.py", line 185, in run
     return_code = self.take_action(parsed_args) or 0
   File "/usr/lib/python3.6/site-packages/tripleoclient/v1/tripleo_validator.py", 
 line 478, in take_action
     print(json.dumps(p['tasks'],
 KeyError: 'tasks'
 'tasks'
 (undercloud) [stack@undercloud-0 ~]$