error[E0277]: the trait bound `Error: std::cmp::Eq` is not satisfied
  --> $DIR/derives-span-Eq-struct.rs:9:5
   |
LL |     x: 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`.