Automatically published version of the package `rustc_error_codes` in the rust-lang/rust repository from commit 30ca215b4e38b32aa7abdd635c5e2d56f5724494 The publishing script for this crate lives at: https://github.com/alexcrichton/rustc-auto-publish
A `#![feature]` attribute was declared multiple times.
Erroneous code example:
```compile_fail,E0636
#![allow(stable_features)]#![feature(rust1)]#![feature(rust1)] // error: the feature `rust1` has already been declared```