error[E0412]: cannot find type `Missing` in this scope
  --> $DIR/ice-struct-tail-normalization-113272.rs:5:25
   |
LL | impl Trait for () where Missing: Trait {}
   |                         ^^^^^^^ not found in this scope

error[E0046]: not all trait items implemented, missing: `RefTarget`
  --> $DIR/ice-struct-tail-normalization-113272.rs:5:1
   |
LL |     type RefTarget;
   |     -------------- `RefTarget` from trait
...
LL | impl Trait for () where Missing: Trait {}
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ missing `RefTarget` in implementation

error: aborting due to 2 previous errors

Some errors have detailed explanations: E0046, E0412.
For more information about an error, try `rustc --explain E0046`.