LL | #[derive(B)]
| - the attribute is introduced here
|
- = note: `#[warn(legacy_derive_helpers)]` on by default
= warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
= note: for more information, see issue #79202 <https://github.com/rust-lang/rust/issues/79202>
+ = note: `#[warn(legacy_derive_helpers)]` on by default
warning: derive helper attribute is used before it is introduced
--> $DIR/proc-macro-attributes.rs:10:3