error[E0277]: the trait bound `Error: std::cmp::Eq` is not satisfied --> $DIR/derives-span-Eq-enum.rs:10:6 | LL | Error | ^^^^^ the trait `std::cmp::Eq` is not implemented for `Error` | = note: required by `std::cmp::AssertParamIsEq` error: aborting due to previous error For more information about this error, try `rustc --explain E0277`.