error: implementation of `Foo` is not general enough
  --> $DIR/issue-97997.rs:13:5
   |
LL |     <fn(&u8) as Foo>::ASSOC;
   |     ^^^^^^^^^^^^^^^^^^^^^^^ implementation of `Foo` is not general enough
   |
   = note: `Foo` would have to be implemented for the type `for<'r> fn(&'r u8)`
   = note: ...but `Foo` is actually implemented for the type `fn(&'0 u8)`, for some specific lifetime `'0`

error: implementation of `Foo` is not general enough
  --> $DIR/issue-97997.rs:13:5
   |
LL |     <fn(&u8) as Foo>::ASSOC;
   |     ^^^^^^^^^^^^^^^^^^^^^^^ implementation of `Foo` is not general enough
   |
   = note: `Foo` would have to be implemented for the type `for<'r> fn(&'r u8)`
   = note: ...but `Foo` is actually implemented for the type `fn(&'0 u8)`, for some specific lifetime `'0`

error: aborting due to 2 previous errors