error[E0119]: conflicting implementations of trait `MyTrait` for type `MyStruct` --> $DIR/coherence_copy_like_err_struct.rs:19:1 | LL | impl MyTrait for T { } | ---------------------------------- first implementation here ... LL | impl MyTrait for lib::MyStruct { } | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `MyStruct` | = note: upstream crates may add a new impl of trait `lib::MyCopy` for type `lib::MyStruct` in future versions error: aborting due to previous error For more information about this error, try `rustc --explain E0119`.