error: unconstrained opaque type
  --> $DIR/recursive-type-alias-impl-trait-declaration-too-subtle.rs:4:16
   |
LL |     type Foo = impl PartialEq<(Foo, i32)>;
   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: `Foo` must be used in combination with a concrete type within the same module

error: unconstrained opaque type
  --> $DIR/recursive-type-alias-impl-trait-declaration-too-subtle.rs:17:16
   |
LL |     type Foo = impl PartialEq<(Foo, i32)>;
   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: `Foo` must be used in combination with a concrete type within the same module

error[E0276]: impl has stricter requirements than trait
  --> $DIR/recursive-type-alias-impl-trait-declaration-too-subtle.rs:23:9
   |
LL |         fn eq(&self, _other: &(Bar, i32)) -> bool {
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ impl has extra requirement `b::Bar: PartialEq<(b::Bar, i32)>`

error: aborting due to 3 previous errors

For more information about this error, try `rustc --explain E0276`.