1 error[E0277]: the trait bound `impl Future<Output = ()>: Copy` is not satisfied
2 --> $DIR/issue-55872-3.rs:14:20
4 LL | fn foo<T>() -> Self::E {
5 | ^^^^^^^ the trait `Copy` is not implemented for `impl Future<Output = ()>`
7 error: aborting due to previous error
9 For more information about this error, try `rustc --explain E0277`.