Announcing Rust 1.34.1

Apr. 25, 2019 · The Rust Release Team

The Rust team is happy to announce a new version of Rust, 1.34.1, and a new version of rustup, 1.18.1. Rust is a programming language that is empowering everyone to build reliable and efficient software.

If you have a previous version of Rust installed via rustup, getting Rust 1.34.1 and rustup 1.18.1 is as easy as:

$ rustup update stable

If you don't have it already, you can get rustup from the appropriate page on our website.

What's in 1.34.1 stable

This patch release fixes two false positives and a panic when checking macros in Clippy. Clippy is a tool which provides a collection of lints to catch common mistakes and improve your Rust code.

False positive in clippy::redundant_closure

A false positive in the redundant_closure lint was fixed. The lint did not take into account differences in the number of borrows.

In the following snippet, the method required expects dep: &D but the actual type of dep is &&D:

dependencies.iter().filter(|dep| dep.required());

Clippy erronously suggested .filter(Dependency::required), which is rejected by the compiler due to the difference in borrows.

False positive in clippy::missing_const_for_fn

Another false positive in the missing_const_for_fn lint was fixed. This lint did not take into account that functions inside trait implementations cannot be const fns. For example, when given the following snippet, the lint would trigger:

#[derive(PartialEq, Eq)] // warning: this could be a const_fn
struct Point(isize, isize);

impl std::ops::Add for Point {
    type Output = Self;

    fn add(self, other: Self) -> Self { // warning: this could be a const_fn
        Point(self.0 + other.0, self.1 + other.1)

What's new in rustup 1.18.1

A recent rustup release, 1.18.0, introduced a regression that prevented installing Rust through the shell script on older platforms. A patch was released that fixes the issue, avoiding to force TLS v1.2 on the platforms that don't support it.

You can check out other rustup changes in its full release notes.