After upgrading to 20.12.0 from what was probably the very last version before this, I am now seeing errors in the logs on startup. Some of them like:
2020-12-18 16:41:14 WARNING (Recorder) [homeassistant.components.recorder.migration] Database is about to upgrade. Schema version: 9
2020-12-18 16:41:14 ERROR (Recorder) [homeassistant.components.recorder.util] Error executing query: (MySQLdb._exceptions.IntegrityError) (1062, "Duplicate entry '0' for key 'PRIMARY'")
[SQL: INSERT INTO schema_changes (schema_version, changed) VALUES (%s, %s)]
[parameters: (10, datetime.datetime(2020, 12, 18, 22, 41, 14, 221793, tzinfo=datetime.timezone.utc))]
(Background on this error at: http://sqlalche.me/e/13/gkpj)
2020-12-18 16:41:14 ERROR (Recorder) [homeassistant.components.recorder] Error during connection setup: (MySQLdb._exceptions.IntegrityError) (1062, "Duplicate entry '0' for key 'PRIMARY'")
[SQL: INSERT INTO schema_changes (schema_version, changed) VALUES (%s, %s)]
[parameters: (10, datetime.datetime(2020, 12, 18, 22, 41, 14, 221793, tzinfo=datetime.timezone.utc))]
(Background on this error at: http://sqlalche.me/e/13/gkpj) (retrying in 3 seconds)
2020-12-18 16:41:17 WARNING (Recorder) [homeassistant.components.recorder.migration] Database is about to upgrade. Schema version: 9
2020-12-18 16:41:17 ERROR (Recorder) [homeassistant.components.recorder.util] Error executing query: (MySQLdb._exceptions.IntegrityError) (1062, "Duplicate entry '0' for key 'PRIMARY'")
[SQL: INSERT INTO schema_changes (schema_version, changed) VALUES (%s, %s)]
[parameters: (10, datetime.datetime(2020, 12, 18, 22, 41, 17, 287006, tzinfo=datetime.timezone.utc))]
(Background on this error at: http://sqlalche.me/e/13/gkpj)
2020-12-18 16:41:17 ERROR (Recorder) [homeassistant.components.recorder] Error during connection setup: (MySQLdb._exceptions.IntegrityError) (1062, "Duplicate entry '0' for key 'PRIMARY'")
[SQL: INSERT INTO schema_changes (schema_version, changed) VALUES (%s, %s)]
[parameters: (10, datetime.datetime(2020, 12, 18, 22, 41, 17, 287006, tzinfo=datetime.timezone.utc))]
(Background on this error at: http://sqlalche.me/e/13/gkpj) (retrying in 3 seconds)
2020-12-18 16:41:20 WARNING (Recorder) [homeassistant.components.recorder.migration] Database is about to upgrade. Schema version: 9
2020-12-18 16:41:20 ERROR (Recorder) [homeassistant.components.recorder.util] Error executing query: (MySQLdb._exceptions.IntegrityError) (1062, "Duplicate entry '0' for key 'PRIMARY'")
[SQL: INSERT INTO schema_changes (schema_version, changed) VALUES (%s, %s)]
[parameters: (10, datetime.datetime(2020, 12, 18, 22, 41, 20, 369233, tzinfo=datetime.timezone.utc))]
(Background on this error at: http://sqlalche.me/e/13/gkpj)