Error "Unexpected exception ValueError during processing: dictionary update sequence element #1 has length 1; 2 is required" after introspection

Issue

• While deploying RHOSP 16.1, introspection failed with error message:

"Unexpected exception ValueError during processing: dictionary update sequence element #1 has length 1; 2 is required"

• At /var/log/containers/ironic-inspector/ironic-inspector.log the following lines can be seen:

2021-03-04 16:24:26.474 7 DEBUG ironic_inspector.node_cache [-] [node: xxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxx state processing] Committing fields: {'state': 'error'} _commit /usr/lib/python3.6/site-packages/ironic_inspector/node_cache.py:150
2021-03-04 16:24:26.480 7 DEBUG ironic_inspector.node_cache [-] [node: xxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxx state error] Committing fields: {'finished_at': datetime.datetime(2021, 3, 4, 10, 54, 26, 473942), 'error': 'dictionary update sequence element #1 has length 1; 2 is required'} _commit /usr/lib/python3.6/site-packages/ironic_inspector/node_cache.py:150