error: `MutexGuard` held across a suspend point, but should not be
  --> $DIR/mutex.rs:8:9
   |
LL |     let _guard = m.lock().unwrap();
   |         ^^^^^^
LL |     other().await;
   |             ----- the value is held across this suspend point
   |
note: holding a MutexGuard across suspend points can cause deadlocks, delays, and cause Futures to not implement `Send`
  --> $DIR/mutex.rs:8:9
   |
LL |     let _guard = m.lock().unwrap();
   |         ^^^^^^
help: consider using a block (`{ ... }`) to shrink the value's scope, ending before the suspend point
  --> $DIR/mutex.rs:8:9
   |
LL |     let _guard = m.lock().unwrap();
   |         ^^^^^^
note: the lint level is defined here
  --> $DIR/mutex.rs:3:9
   |
LL | #![deny(must_not_suspend)]
   |         ^^^^^^^^^^^^^^^^

error: aborting due to previous error