error[E0038]: the trait `Bar` cannot be made into an object --> $DIR/issue-28576.rs:7:12 | LL | / dyn Bar LL | | | |________________________^ `Bar` cannot be made into an object | note: for a trait to be "object safe" it needs to allow building a vtable to allow the call to be resolvable dynamically; for more information visit --> $DIR/issue-28576.rs:5:16 | LL | pub trait Bar: Foo { | --- ^^^^^^^^^^^^^ | | | | | | | ...because it uses `Self` as a type parameter | | ...because it uses `Self` as a type parameter | this trait cannot be made into an object... error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0038`.