testcommonswiki is missing the column cuc_only_for_read_old in the table cu_changes. The column was added to production in T329203: Add new column cuc_only_for_read_old to cu_changes for migration purposes to wmf wikis, but this wiki was missed.
This can be seen in the drift tracker report at https://drift-tracker.toolforge.org/report/checkuser/, including the relevant DB hosts.
- ALTERs to run: https://gerrit.wikimedia.org/r/plugins/gitiles/mediawiki/extensions/CheckUser/+/022f35b72c3b379394483101d78a78c761677a35/schema/mysql/patch-cu_changes-add-cuc_only_for_read_old.sql
- Where to run those changes: testcommonswiki
- When to run those changes: Ideally quickly, as this holds up writing new on group0 wikis.
- If the schema change is backwards compatible: Yes.
- If the schema change has been tested already on some of the test/beta wikis: Schema change is applied to all production wikis, except from testcommonswiki. This column is being written to on testwiki.
- if the data should be made available on the labs replicas and/or dumps: Everything is private