Rust errors / Attributes, macros and features
Rust compiler error · checked with rustc 1.99.0
Rust error E0546: missing 'feature'
What it meansThe feature value is missing in a stability attribute.
What rustc prints
error[E0546]: missing 'feature'
--> main.rs:5:1
|
5 | #[unstable(issue = "none")] // invalid
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^Real output of rustc 1.99.0 compiling the official example below (2021 edition). Your names and line numbers will differ; the first line is the part to match.
E0546Attributes, macros and features
Activein rustc 1.99.0
5related errors linked below
The compiler team's explanation
The feature value is missing in a stability attribute.
Erroneous code example:
#![feature(staged_api)]
#![allow(internal_features)]
#![stable(since = "1.0.0", feature = "test")]
#[unstable(issue = "none")] // invalid
fn unstable_fn() {}
#[stable(since = "1.0.0")] // invalid
fn stable_fn() {}To fix this issue, you need to provide the feature field. Example:
#![feature(staged_api)]
#![allow(internal_features)]
#![stable(since = "1.0.0", feature = "test")]
#[unstable(feature = "unstable_fn", issue = "none")] // ok!
fn unstable_fn() {}
#[stable(feature = "stable_fn", since = "1.0.0")] // ok!
fn stable_fn() {}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.
From rustc --explain E0546 (1.99.0), part of the Rust project, MIT or Apache-2.0. Official page.
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