error[E0119]: conflicting implementations of trait `Trait` for type `Wrapper` --> $DIR/coherence-with-coroutine.rs:21:1 | LL | impl Trait for Wrapper {} | --------------------------------------- first implementation here LL | impl Trait for Wrapper {} | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `Wrapper` error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0119`.