error[E0277]: `()` is not a future
  --> $DIR/issue-96555.rs:4:13
   |
LL |     m::f1().await;
   |     ------- ^^^^^ `()` is not a future
   |     |
   |     this call returns `()`
   |
   = help: the trait `Future` is not implemented for `()`, which is required by `(): IntoFuture`
   = note: () must be a future or must implement `IntoFuture` to be awaited
   = note: required for `()` to implement `IntoFuture`
help: remove the `.await`
   |
LL -     m::f1().await;
LL +     m::f1();
   |
help: alternatively, consider making `fn f1` asynchronous
   |
LL |     pub async fn f1() {}
   |         +++++

error[E0277]: `()` is not a future
  --> $DIR/issue-96555.rs:5:13
   |
LL |     m::f2().await;
   |     ------- ^^^^^ `()` is not a future
   |     |
   |     this call returns `()`
   |
   = help: the trait `Future` is not implemented for `()`, which is required by `(): IntoFuture`
   = note: () must be a future or must implement `IntoFuture` to be awaited
   = note: required for `()` to implement `IntoFuture`
help: remove the `.await`
   |
LL -     m::f2().await;
LL +     m::f2();
   |
help: alternatively, consider making `fn f2` asynchronous
   |
LL |     pub(crate) async fn f2() {}
   |                +++++

error[E0277]: `()` is not a future
  --> $DIR/issue-96555.rs:6:13
   |
LL |     m::f3().await;
   |     ------- ^^^^^ `()` is not a future
   |     |
   |     this call returns `()`
   |
   = help: the trait `Future` is not implemented for `()`, which is required by `(): IntoFuture`
   = note: () must be a future or must implement `IntoFuture` to be awaited
   = note: required for `()` to implement `IntoFuture`
help: remove the `.await`
   |
LL -     m::f3().await;
LL +     m::f3();
   |
help: alternatively, consider making `fn f3` asynchronous
   |
LL |     pub async
   |         +++++

error: aborting due to 3 previous errors

For more information about this error, try `rustc --explain E0277`.