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# Error code E0544

Multiple stability attributes were declared on the same item.

Erroneous code example:

    #![allow(unused)]
    #![feature(staged_api)]
    #![allow(internal_features)]
    #![stable(since = "1.0.0", feature = "rust1")]

    fn main() {
    #[stable(feature = "rust1", since = "1.0.0")]
    #[stable(feature = "test", since = "2.0.0")] // invalid
    fn foo() {}
    }

To fix this issue, ensure that each item has at most one stability attribute.

    #![allow(unused)]
    #![feature(staged_api)]
    #![allow(internal_features)]
    #![stable(since = "1.0.0", feature = "rust1")]

    fn main() {
    #[stable(feature = "test", since = "2.0.0")] // ok!
    fn foo() {}
    }

See the How Rust is Made and “Nightly Rust” appendix of the Book and the Stability attributes section of the Rustc Dev Guide for more details.