error[E0774]: `derive` may only be applied to structs, enums and unions --> $DIR/issue-43023.rs:4:5 | LL | #[derive(Debug)] | ^^^^^^^^^^^^^^^^ error[E0774]: `derive` may only be applied to structs, enums and unions --> $DIR/issue-43023.rs:11:5 | LL | #[derive(Debug)] | ^^^^^^^^^^^^^^^^ error[E0774]: `derive` may only be applied to structs, enums and unions --> $DIR/issue-43023.rs:16:5 | LL | #[derive(Debug)] | ^^^^^^^^^^^^^^^^ error: aborting due to 3 previous errors For more information about this error, try `rustc --explain E0774`.