{"ast_node_type":"other","tokens":[{"end":86,"kind":"keyword","start":0,"text":"trace!(universe"}]}
        trace!(universe = ?self.max_nameable_universe(self.constraint_sccs.scc(fr1)));
        trace!(scc = ?self.constraint_sccs.scc(fr1));
        self.find_constraint_paths_between_regions(fr1, |r| {