error[E0277]: the trait bound `(): Foo` is not satisfied --> $DIR/point-at-failing-nested.rs:22:17 | LL | needs_foo::<()>(); | ^^ the trait `Bar` is not implemented for `()` | help: this trait has no implementations, consider adding one --> $DIR/point-at-failing-nested.rs:4:1 | LL | trait Bar {} | ^^^^^^^^^ note: required for `()` to implement `Foo` --> $DIR/point-at-failing-nested.rs:9:12 | LL | impl Foo for T | ^^^ ^ ... LL | U: Bar, | --- unsatisfied trait bound introduced here note: required by a bound in `needs_foo` --> $DIR/point-at-failing-nested.rs:20:17 | LL | fn needs_foo() {} | ^^^ required by this bound in `needs_foo` error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0277`.