error[E0275]: overflow evaluating the requirement `Box>>: NotAuto` --> $DIR/lifetime.rs:29:5 | LL | is_send::>>(); | ^^^^^^^^^^^^^^^^^^^^^^^^ | note: required for `X>` to implement `NotAuto` --> $DIR/lifetime.rs:19:12 | LL | impl NotAuto for X where T::P: NotAuto {} | ^^^^^^^ ^^^^ ------- unsatisfied trait bound introduced here note: required by a bound in `is_send` --> $DIR/lifetime.rs:23:15 | LL | fn is_send() {} | ^^^^^^^ required by this bound in `is_send` error: aborting due to previous error For more information about this error, try `rustc --explain E0275`.