--- /dev/null
+warning: the feature `type_alias_impl_trait` is incomplete and may not be safe to use and/or cause compiler crashes
+ --> $DIR/generic_duplicate_param_use2.rs:3:32
+ |
+LL | #![cfg_attr(full_tait, feature(type_alias_impl_trait))]
+ | ^^^^^^^^^^^^^^^^^^^^^
+ |
+ = note: `#[warn(incomplete_features)]` on by default
+ = note: see issue #63063 <https://github.com/rust-lang/rust/issues/63063> for more information
+
+error: non-defining opaque type use in defining scope
+ --> $DIR/generic_duplicate_param_use2.rs:13:27
+ |
+LL | fn one<T: Debug>(t: T) -> Two<T, T> {
+ | ^^^^^^^^^
+ |
+note: type used multiple times
+ --> $DIR/generic_duplicate_param_use2.rs:11:10
+ |
+LL | type Two<T, U> = impl Debug;
+ | ^ ^
+
+error: aborting due to previous error; 1 warning emitted
+