SQL provisioner membership requires the group column to be a standard core field

The group-related column when provisioning to a membership table needs to be one of the core (id, name, displayName, ...) fields. If it's a translation script, there is an error "Error: Cant find membership column to use for matching when it involves groups". The source code looks through all the provisioned columns, and only accepts if it can find one with a GrouperProvisioningGroup value.

Note it's not about uniqueness, since it allows the value to be displayExtension, which is far from guaranteed unique.

It's an easy workaround just to add another column that can store a core value (ideally the name, id, or idIndex). But it's not documented that it's required, and the error message is oddly written.