// Support for legacy derive helpers is limited and heuristic-based // (that's exactly the reason why they are deprecated). // edition:2018 // aux-build:test-macros.rs #[macro_use] extern crate test_macros; use derive as my_derive; #[my_derive(Empty)] #[empty_helper] // OK struct S1; // Legacy helper detection doesn't see through `derive` renaming. #[empty_helper] //~ ERROR cannot find attribute `empty_helper` in this scope #[my_derive(Empty)] struct S2; fn main() {}