Rust

The Rust provider tracks the toolchain releases published at static.rust-lang.org, reading the manifest index (static.rust-lang.org/manifests.txt) that lists every channel manifest ever published. It resolves the bare toolchain version, such as a RUST_VERSION CI variable, a mise rust pin, a pinned channel in rust-toolchain.toml, or a rust-version floor in Cargo.toml. A rust:1.97-slim container tag is a Docker image, handled by the Docker provider.

# clover: provider=rust constraint=minor
RUST_VERSION: 1.97.0

Keys

The manifest index is public, so the Rust provider needs no authentication. It is selected explicitly with provider=rust, or inferred from a rust pin in a mise configuration or .tool-versions file, a version-pinned channel in rust-toolchain.toml, or a rust-version floor in Cargo.toml. Like a requires-python floor, rust-version is bumped in place with its precision preserved, so "1.70" advances only when a new minor line ships.

Each release is dated by the directory its manifest was published under, so cooldown works: a version is held back until it has aged past the window. The whole release history arrives in one response, so Clover always sees every release and --deep has nothing extra to fetch. The index starts at Rust 1.8.0 and its numbered beta snapshots at 1.75.0, so earlier releases predate it and cannot be resolved.

Channels

Rust ships on three release channels. By default Clover tracks stable, so the newest release satisfying the constraint wins. channel=beta lists the numbered beta snapshots (1.98.0-beta.1) instead:

# clover: provider=rust channel=beta
RUST_VERSION: 1.98.0-beta.1

A beta version’s dash-suffix behaves like any other suffix on a line: selection stays on the numbered track already written there, so 1.98.0-beta.1 advances to the next cycle’s first snapshot (1.99.0-beta.1) as soon as it ships. Since every cycle publishes a beta.1, that is the number to pin. Moving across numbers instead, so the line always holds the newest snapshot whatever its number, takes an explicit include to unpin the track and prerelease=true because betas then face the prerelease gate:

# clover: provider=rust channel=beta include=*-beta.* prerelease=true
RUST_VERSION: 1.98.0-beta.1

The nightly channel is not trackable: a nightly build is a dated snapshot (nightly-2026-07-11) with no version of its own, so there is nothing version-shaped to resolve, and channel=nightly is rejected.

Checksums

Rust publishes a .sha256 file beside every release artifact at a predictable URL, so a follower can keep a checksum in lockstep with the version by templating sha256-url with <version> and selecting the artifact with pattern:

# clover: provider=rust id=rust constraint=minor
RUST_VERSION: 1.97.0

# clover: from=rust value=sha256 sha256-url=https://static.rust-lang.org/dist/rust-<version>-x86_64-unknown-linux-gnu.tar.xz.sha256 pattern=rust-<version>-x86_64-unknown-linux-gnu.tar.xz
RUST_SHA256: 0000000000000000000000000000000000000000000000000000000000000000

The checksum is refreshed only when the version it follows actually changes, so the two never drift out of step, and a digest that was once pinned never moves on its own. Pass --force (or set run.force) to deliberately re-pin it when an unchanged version’s artifact was legitimately re-published.