error: lifetime in trait object type must be followed by `+`
  --> $DIR/gat-trait-path-parenthesised-args.rs:8:29
   |
LL | fn foo<'a>(arg: Box<dyn X<Y('a) = &'a ()>>) {}
   |                             ^^

error: parenthesized generic arguments cannot be used in associated type constraints
  --> $DIR/gat-trait-path-parenthesised-args.rs:8:27
   |
LL | fn foo<'a>(arg: Box<dyn X<Y('a) = &'a ()>>) {}
   |                           ^^^^^

warning: the feature `generic_associated_types` is incomplete and may not be safe to use and/or cause compiler crashes
  --> $DIR/gat-trait-path-parenthesised-args.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

warning: trait objects without an explicit `dyn` are deprecated
  --> $DIR/gat-trait-path-parenthesised-args.rs:8:29
   |
LL | fn foo<'a>(arg: Box<dyn X<Y('a) = &'a ()>>) {}
   |                             ^^ help: use `dyn`: `dyn 'a`
   |
   = note: `#[warn(bare_trait_objects)]` on by default
   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2021 edition!
   = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>

error[E0107]: this associated type takes 1 lifetime argument but 0 lifetime arguments were supplied
  --> $DIR/gat-trait-path-parenthesised-args.rs:8:27
   |
LL | fn foo<'a>(arg: Box<dyn X<Y('a) = &'a ()>>) {}
   |                           ^ expected 1 lifetime argument
   |
note: associated type defined here, with 1 lifetime parameter: `'a`
  --> $DIR/gat-trait-path-parenthesised-args.rs:5:8
   |
LL |   type Y<'a>;
   |        ^ --
help: add missing lifetime argument
   |
LL | fn foo<'a>(arg: Box<dyn X<Y('a, 'a) = &'a ()>>) {}
   |                             ^^^

error[E0107]: this associated type takes 0 generic arguments but 1 generic argument was supplied
  --> $DIR/gat-trait-path-parenthesised-args.rs:8:27
   |
LL | fn foo<'a>(arg: Box<dyn X<Y('a) = &'a ()>>) {}
   |                           ^-------------- help: remove these generics
   |                           |
   |                           expected 0 generic arguments
   |
note: associated type defined here, with 0 generic parameters
  --> $DIR/gat-trait-path-parenthesised-args.rs:5:8
   |
LL |   type Y<'a>;
   |        ^

error: aborting due to 4 previous errors; 2 warnings emitted

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