A library for querying the version of a rustc compiler.

This can be used by build scripts or other tools dealing with Rust sources to make decisions based on the version of the compiler.

Travis-CI Status

Getting Started

rustc-version-rs is available on It is recommended to look there for the newest released version, as well as links to the newest builds of the docs.

At the point of the last update of this README, the latest published version could be used like this:

Add the following dependency to your Cargo manifest...

rustc_version = "0.2"

...and see the docs for how to use it.


// This could be a cargo build script

extern crate rustc_version;
use rustc_version::{version, version_meta, Channel, Version};

fn main() {
    // Assert we haven't travelled back in time
    assert!(version().unwrap().major >= 1);

    // Set cfg flags depending on release channel
    match version_meta().unwrap().channel {
        Channel::Stable => {
        Channel::Beta => {
        Channel::Nightly => {
        Channel::Dev => {

    // Check for a minimum version
    if version().unwrap() >= Version::parse("1.4.0").unwrap() {


Licensed under either of

at your option.


Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.