error[E0592]: duplicate definitions with name `dummy` --> $DIR/coherence-overlap-issue-23516-inherent.rs:9:25 | LL | impl Cake { fn dummy(&self) { } } | ^^^^^^^^^^^^^^^^^^^ duplicate definitions for `dummy` LL | LL | impl Cake> { fn dummy(&self) { } } | ------------------- other definition for `dummy` | = note: downstream crates may implement trait `Sugar` for type `std::boxed::Box<_>` error: aborting due to previous error For more information about this error, try `rustc --explain E0592`.