error[E0277]: the trait bound `{async block@$DIR/issue-55872-3.rs:15:9: 15:17}: Copy` is not satisfied
  --> $DIR/issue-55872-3.rs:13:20
   |
LL |     fn foo<T>() -> Self::E {
   |                    ^^^^^^^ the trait `Copy` is not implemented for `{async block@$DIR/issue-55872-3.rs:15:9: 15:17}`

error: aborting due to previous error

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