error[E0720]: cannot resolve opaque type
  --> $DIR/recursive-impl-trait-type-direct.rs:5:14
   |
LL | fn test() -> impl Sized {
   |              ^^^^^^^^^^ recursive opaque type
LL |
LL |     test()
   |     ------ returning here with type `impl Sized`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0720`.