warning: derive helper attribute is used before it is introduced
  --> $DIR/issue-75930-derive-cfg.rs:19:3
   |
LL | #[print_helper(a)]
   |   ^^^^^^^^^^^^
...
LL | #[derive(Print)]
   |          ----- the attribute is introduced here
   |
   = 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/issue-75930-derive-cfg.rs:19:3
   |
LL | #[print_helper(a)]
   |   ^^^^^^^^^^^^
...
LL | #[derive(Print)]
   |          ----- the attribute is introduced here
   |
   = 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>

warning: 2 warnings emitted