Intermittent exit issues

[khsa1]

Intermittently, all of the plugins exit with code 0 but the engine remains running. This happened most recently on a P100 node on CHI@TACC.

Unclear if this is related, but the power monitoring plugin prints this message before exiting:

Metadata validation failed: '' is not one of ['image_scoring_plugin', 'image_generating_plugin', 'power_monitor_plugin', 'oracle_plugin', 'engine']

Failed validating 'enum' in schema['properties']['plugins']['items']['properties']['name']:
    {'enum': ['image_scoring_plugin',
              'image_generating_plugin',
              'power_monitor_plugin',
              'oracle_plugin',
              'engine'],
     'type': 'string'}

On instance['plugins'][0]['name']:
    ''