1 error[E0038]: the trait `B` cannot be made into an object
2 --> $DIR/issue-38404.rs:13:15
4 LL | trait C<T>: A<B<T, Output=usize>> {}
5 | ^^^^^^^^^^^^^^^^^^ the trait `B` cannot be made into an object
7 = note: the trait cannot use `Self` as a type parameter in the supertraits or where-clauses
9 error: aborting due to previous error
11 For more information about this error, try `rustc --explain E0038`.