warning: unused coroutine that must be used
  --> $DIR/issue-48623-coroutine.rs:15:18
   |
LL |     #[coroutine] move || { d; yield; &mut *r };
   |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: coroutines are lazy and do nothing unless resumed
   = note: `#[warn(unused_must_use)]` on by default

warning: 1 warning emitted