warning: the feature `generic_associated_types` is incomplete and may not be safe to use and/or cause compiler crashes
  --> $DIR/trait-path-type-error-once-implemented.rs:1:12
   |
LL | #![feature(generic_associated_types)]
   |            ^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: `#[warn(incomplete_features)]` on by default
   = note: see issue #44265 <https://github.com/rust-lang/rust/issues/44265> for more information

error[E0107]: this associated type takes 1 lifetime argument but 0 lifetime arguments were supplied
  --> $DIR/trait-path-type-error-once-implemented.rs:9:29
   |
LL |   fn f2<'a>(arg : Box<dyn X<Y<1> = &'a ()>>) {}
   |                             ^ expected 1 lifetime argument
   |
note: associated type defined here, with 1 lifetime parameter: `'a`
  --> $DIR/trait-path-type-error-once-implemented.rs:5:10
   |
LL |     type Y<'a>;
   |          ^ --
help: add missing lifetime argument
   |
LL |   fn f2<'a>(arg : Box<dyn X<Y<'a, 1> = &'a ()>>) {}
   |                               ^^^

error[E0107]: this associated type takes 0 generic arguments but 1 generic argument was supplied
  --> $DIR/trait-path-type-error-once-implemented.rs:9:29
   |
LL |   fn f2<'a>(arg : Box<dyn X<Y<1> = &'a ()>>) {}
   |                             ^--- help: remove these generics
   |                             |
   |                             expected 0 generic arguments
   |
note: associated type defined here, with 0 generic parameters
  --> $DIR/trait-path-type-error-once-implemented.rs:5:10
   |
LL |     type Y<'a>;
   |          ^

error: aborting due to 2 previous errors; 1 warning emitted

For more information about this error, try `rustc --explain E0107`.