error: at least one trait must be specified
  --> $DIR/generic_underconstrained2.rs:8:45
   |
LL | type Underconstrained<T: std::fmt::Debug> = impl 'static;
   |                                             ^^^^^^^^^^^^

error: at least one trait must be specified
  --> $DIR/generic_underconstrained2.rs:17:46
   |
LL | type Underconstrained2<T: std::fmt::Debug> = impl 'static;
   |                                              ^^^^^^^^^^^^

warning: the feature `type_alias_impl_trait` is incomplete and may not be safe to use and/or cause compiler crashes
  --> $DIR/generic_underconstrained2.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[E0277]: `U` doesn't implement `Debug`
  --> $DIR/generic_underconstrained2.rs:12:33
   |
LL | type Underconstrained<T: std::fmt::Debug> = impl 'static;
   |                          --------------- required by this bound in `Underconstrained`
...
LL | fn underconstrained<U>(_: U) -> Underconstrained<U> {
   |                                 ^^^^^^^^^^^^^^^^^^^ `U` cannot be formatted using `{:?}` because it doesn't implement `Debug`
   |
help: consider restricting type parameter `U`
   |
LL | fn underconstrained<U: Debug>(_: U) -> Underconstrained<U> {
   |                      ^^^^^^^

error[E0277]: `V` doesn't implement `Debug`
  --> $DIR/generic_underconstrained2.rs:21:43
   |
LL | type Underconstrained2<T: std::fmt::Debug> = impl 'static;
   |                           --------------- required by this bound in `Underconstrained2`
...
LL | fn underconstrained2<U, V>(_: U, _: V) -> Underconstrained2<V> {
   |                                           ^^^^^^^^^^^^^^^^^^^^ `V` cannot be formatted using `{:?}` because it doesn't implement `Debug`
   |
help: consider restricting type parameter `V`
   |
LL | fn underconstrained2<U, V: Debug>(_: U, _: V) -> Underconstrained2<V> {
   |                          ^^^^^^^

error: aborting due to 4 previous errors; 1 warning emitted

For more information about this error, try `rustc --explain E0277`.