error: this `async` block contains no `.await`
  --> $DIR/async_block_without_await.rs:17:14
   |
LL |     let _f = async {};
   |              ^^^^^^^^
   |
   = help: consider removing the `async` block or adding the missing `.await`
   = note: `-D async-block-without-await` implied by `-D warnings`
   = help: to override `-D warnings` add `#[allow(async_block_without_await)]`

error: this `async` block contains no `.await`
  --> $DIR/async_block_without_await.rs:20:14
   |
LL |     let _f = async { 42 };
   |              ^^^^^^^^^^^^
   |
   = help: consider removing the `async` block or adding the missing `.await`

error: this `async` block contains no `.await`
  --> $DIR/async_block_without_await.rs:23:14
   |
LL |       let _f = async move {
   |  ______________^
LL | |         let x = 1;
LL | |         x + 2
LL | |     };
   | |_____^
   |
   = help: consider removing the `async` block or adding the missing `.await`

error: this `async` block contains no `.await`
  --> $DIR/async_block_without_await.rs:29:14
   |
LL |     let _f = async { sync_fn() };
   |              ^^^^^^^^^^^^^^^^^^^
   |
   = help: consider removing the `async` block or adding the missing `.await`

error: this `async` block contains no `.await`
  --> $DIR/async_block_without_await.rs:34:21
   |
LL |         let inner = async { 42 };
   |                     ^^^^^^^^^^^^
   |
   = help: consider removing the `async` block or adding the missing `.await`

error: this `async` block contains no `.await`
  --> $DIR/async_block_without_await.rs:77:9
   |
LL |         async { 42 }
   |         ^^^^^^^^^^^^
   |
   = help: consider removing the `async` block or adding the missing `.await`

error: aborting due to 6 previous errors