error[E0491]: in type `&'a &'b ()`, reference has a longer lifetime than the data it references
  --> $DIR/impl-header-unnormalized-types.rs:15:18
   |
LL |     type Assoc = &'a &'b ();
   |                  ^^^^^^^^^^
   |
note: the pointer is valid for the lifetime `'a` as defined here
  --> $DIR/impl-header-unnormalized-types.rs:14:6
   |
LL | impl<'a, 'b> NeedsWf<'a, 'b> for Foo<<&'a &'b () as GoodBye>::Forget> {
   |      ^^
note: but the referenced data is only valid for the lifetime `'b` as defined here
  --> $DIR/impl-header-unnormalized-types.rs:14:10
   |
LL | impl<'a, 'b> NeedsWf<'a, 'b> for Foo<<&'a &'b () as GoodBye>::Forget> {
   |          ^^

error: aborting due to previous error

For more information about this error, try `rustc --explain E0491`.