#[test] interacts strangely with attribute macros that discard the function #148277
Description
I'm not sure if this is a bug or not.
dep/src/lib.rs:
use proc_macro::TokenStream; #[proc_macro_attribute] pub fn discard(_: TokenStream, _: TokenStream) -> TokenStream { TokenStream::new() }src/lib.rs:
#![allow(dead_code)] fn lol() { panic!("why are you calling me"); } #[test] #[dep::discard] fn lol() {}Running cargo test on this gives the following output:
Finished `test` profile [unoptimized + debuginfo] target(s) in 0.00s Running unittests src/lib.rs (target/debug/deps/foo-ebbeb6822a5b805f) running 1 test test lol ... FAILED failures: ---- lol stdout ---- thread 'lol' (37963) panicked at src/lib.rs:4:5: why are you calling me note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace failures: lol test result: FAILED. 0 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s error: test failed, to rerun pass `--lib` It seems that a#[test] attribute will attempt to call a function with the same name as the annotated function, whether it's the same function or not. It will even try to call a const with the same name, if one is available. This seems rather strange. Not sure what the correct behavior is though.
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rustc --version --verbose:
rustc 1.93.0-nightly (292be5c7c 2025-10-29) binary: rustc commit-hash: 292be5c7c05138d753bbd4b30db7a3f1a5c914f7 commit-date: 2025-10-29 host: aarch64-apple-darwin release: 1.93.0-nightly LLVM version: 21.1.3