macro_attr feature gate error is spanned to the declaration of the macro when it should be the call site #147135
Description
I tried this code:
// foo/src/lib.rs #![feature(macro_attr)] #[macro_export] macro_rules! identity { attr() ( $( $item:tt )* ) => { $( $item )* } }// bar/src/lib.rs #[foo::identity] pub fn problem() {}I expected to see this happen: Error pointing to bar/src/lib.rs:2
Instead, this happened:
error[E0658]: `macro_rules!` attributes are unstable --> /Users/kpreid/Desktop/attr/foo/src/lib.rs:4:1 | 4 | macro_rules! identity { | ^^^^^^^^^^^^^^^^^^^^^ | = note: see issue #83527 <https://github.com/rust-lang/rust/issues/83527> for more information = help: add `#![feature(macro_attr)]` to the crate attributes to enable = note: this compiler was built on 2025-09-27; consider upgrading it if it is out of date For more information about this error, try `rustc --explain E0658`. error: could not compile `bar` (lib) due to 1 previous error Therefore, it is impossible to tell which crate needs the attribute added except by examining Cargo's “could not compile” line.
Meta
rustc --version --verbose:
rustc 1.92.0-nightly (4082d6a3f 2025-09-27) binary: rustc commit-hash: 4082d6a3f0347c2fc4b8c8d5a6a38ed7248fa161 commit-date: 2025-09-27 host: aarch64-apple-darwin release: 1.92.0-nightly LLVM version: 21.1.2 @rustbot label A-macros A-diagnostics A-stability T-compiler