Occasionally when developing new updates for modules, the "schema version" has to be reset back if the local update code failed for some reason. In Drupal 7, this was a straightforward change to the `system` table, where each module was clearly listed with a `schema_version` column that could be changed via Pancakes relatively quickly. In Drupal 8, the approach is slightly different. You can find the value of each module schema in the `key_value` table, anything under the collection `system.schema`.

Recently, I was working on a D8 codebase and getting a pesky error anytime I tried to invoke a composer command:

Just to capture that error in text: