1 The `issue` value is incorrect in a stability attribute.
3 Erroneous code example:
6 #![feature(staged_api)]
7 #![stable(since = "1.0.0", feature = "test")]
9 #[unstable(feature = "_unstable_fn", issue = "0")] // invalid
12 #[rustc_const_unstable(feature = "_unstable_const_fn", issue = "0")] // invalid
13 const fn _unstable_const_fn() {}
16 To fix this issue, you need to provide a correct value in the `issue` field.
20 #![feature(staged_api)]
21 #![stable(since = "1.0.0", feature = "test")]
23 #[unstable(feature = "_unstable_fn", issue = "none")] // ok!
26 #[rustc_const_unstable(feature = "_unstable_const_fn", issue = "1")] // ok!
27 const fn _unstable_const_fn() {}
30 See the [How Rust is Made and “Nightly Rust”][how-rust-made-nightly] appendix
31 of the Book and the [Stability attributes][stability-attributes] section of the
32 Rustc Dev Guide for more details.
34 [how-rust-made-nightly]: https://doc.rust-lang.org/book/appendix-07-nightly-rust.html
35 [stability-attributes]: https://rustc-dev-guide.rust-lang.org/stability.html