error[E0659]: `empty_helper` is ambiguous
  --> $DIR/helper-attr-blocked-by-import-ambig.rs:7:3
   |
LL | #[empty_helper]
   |   ^^^^^^^^^^^^ ambiguous name
   |
   = note: ambiguous because of a name conflict with a derive helper attribute
note: `empty_helper` could refer to the derive helper attribute defined here
  --> $DIR/helper-attr-blocked-by-import-ambig.rs:10:10
   |
LL | #[derive(Empty)]
   |          ^^^^^
note: `empty_helper` could also refer to the attribute macro imported here
  --> $DIR/helper-attr-blocked-by-import-ambig.rs:5:5
   |
LL | use test_macros::empty_attr as empty_helper;
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   = help: use `crate::empty_helper` to refer to this attribute macro unambiguously

warning: derive helper attribute is used before it is introduced
  --> $DIR/helper-attr-blocked-by-import-ambig.rs:7:3
   |
LL | #[empty_helper]
   |   ^^^^^^^^^^^^
...
LL | #[derive(Empty)]
   |          ----- 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

error: aborting due to 1 previous error; 1 warning emitted

For more information about this error, try `rustc --explain E0659`.