check user.search_users behaviour
some code is expecting it to return whoosh documents and then accessing doc[NAME] for example. this code currently fails as it returns Revisions.
some other code is dealing with it, processes the revisions correctly, e.g. by accessing rev.meta[NAME].
decide on which behaviour is correct, then fix all callers.
also check acl behaviour. access to user items might be prohibited by ACLs in a production configuration.