error: unconstrained opaque type
  --> $DIR/type-alias-impl-trait-with-cycle-error2.rs:7:12
   |
LL | type Foo = impl Bar<Foo, Item = Foo>;
   |            ^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: `Foo` must be used in combination with a concrete type within the same module

error: aborting due to previous error