#[cfg(debug_assertions)] build_alert::yellow! {" NOTE: use --release Syn's test suite has some tests that run on every source file and test case in the rust-lang/rust repo, which can be pretty slow in debug mode. Consider running cargo test with `--release` to speed things up. "} #[cfg(not(feature = "all-features"))] build_alert::red! {" ERROR: use --all-features Syn's test suite normally only works with all-features enabled. Run again with `--all-features`, or run with `--features test` to bypass this check. "}