message: Add failing test for cycle revalidation
diff: @@ -122,6 +122,14 @@ fn inner_cycle() {
  );
  }
  +#[test]
  +fn cycle_revalidate() {
  + let mut db = DatabaseImpl::default();
  + assert!(db.cycle_a().is_err());
  + CycleLeafQuery.in_db_mut(&mut db).invalidate(&());
  + assert!(db.cycle_a().is_err());
  +}
  +
  #[test]
  fn parallel_cycle() {
  let _ = env_logger::try_init();
  