| error[E0405]: cannot find trait `CallbackMarker` in this scope | |
| --> $DIR/span-bug-issue-121431.rs:1:21 | |
| | | |
| LL | fn bug<T>() -> impl CallbackMarker< Item = [(); { |_: &mut ()| 3; 4 }] > {} | |
| | ^^^^^^^^^^^^^^ not found in this scope | |
| error: aborting due to 1 previous error | |
| For more information about this error, try `rustc --explain E0405`. |