| error[E0369]: binary operation `==` cannot be applied to type `&Error` | 
 |   --> $DIR/derives-span-PartialEq-enum-struct-variant.rs:9:6 | 
 |    | | 
 | LL | #[derive(PartialEq)] | 
 |    |          --------- in this derive macro expansion | 
 | ... | 
 | LL |      x: Error | 
 |    |      ^^^^^^^^ | 
 |    | | 
 | note: an implementation of `PartialEq` might be missing for `Error` | 
 |   --> $DIR/derives-span-PartialEq-enum-struct-variant.rs:4:1 | 
 |    | | 
 | LL | struct Error; | 
 |    | ^^^^^^^^^^^^ must implement `PartialEq` | 
 | help: consider annotating `Error` with `#[derive(PartialEq)]` | 
 |    | | 
 | LL + #[derive(PartialEq)] | 
 | LL | struct Error; | 
 |    | | 
 |  | 
 | error: aborting due to 1 previous error | 
 |  | 
 | For more information about this error, try `rustc --explain E0369`. |