error[E0046]: not all trait items implemented, missing: `call`
  --> $DIR/location-insensitive-scopes-issue-116657.rs:18:1
   |
LL |     fn call(x: Self) -> Self::Output;
   |     --------------------------------- `call` from trait
...
LL | impl<T: PlusOne> Callable for T {
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ missing `call` in implementation

error: unconstrained opaque type
  --> $DIR/location-insensitive-scopes-issue-116657.rs:22:19
   |
LL |     type Output = impl PlusOne;
   |                   ^^^^^^^^^^^^
   |
   = note: `Output` must be used in combination with a concrete type within the same impl

error[E0700]: hidden type for `impl PlusOne` captures lifetime that does not appear in bounds
  --> $DIR/location-insensitive-scopes-issue-116657.rs:28:5
   |
LL | fn test<'a>(y: &'a mut i32) -> impl PlusOne {
   |         --                     ------------ opaque type defined here
   |         |
   |         hidden type `<&'a mut i32 as Callable>::Output` captures the lifetime `'a` as defined here
LL |     <&mut i32 as Callable>::call(y)
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
help: to declare that `impl PlusOne` captures `'a`, you can add an explicit `'a` lifetime bound
   |
LL | fn test<'a>(y: &'a mut i32) -> impl PlusOne + 'a {
   |                                             ++++

error: aborting due to 3 previous errors

Some errors have detailed explanations: E0046, E0700.
For more information about an error, try `rustc --explain E0046`.