error: unsafe attribute used without unsafe
  --> $DIR/in_2024_compatibility.rs:3:3
   |
LL | #[no_mangle]
   |   ^^^^^^^^^ usage of unsafe attribute
   |
   = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2024!
   = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2024/unsafe-attributes.html>
note: the lint level is defined here
  --> $DIR/in_2024_compatibility.rs:1:9
   |
LL | #![deny(rust_2024_compatibility)]
   |         ^^^^^^^^^^^^^^^^^^^^^^^
   = note: `#[deny(unsafe_attr_outside_unsafe)]` implied by `#[deny(rust_2024_compatibility)]`
help: wrap the attribute in `unsafe(...)`
   |
LL | #[unsafe(no_mangle)]
   |   +++++++         +

error: aborting due to 1 previous error