error[E0728]: `await` is only allowed inside `async` functions and blocks --> $DIR/issue-51751.rs:9:27 | LL | fn main() { | ---- this is not `async` LL | let result = inc(10000); LL | let finished = result.await; | ^^^^^ only allowed inside `async` functions and blocks error: aborting due to previous error For more information about this error, try `rustc --explain E0728`.