cargo-msrv

This crate can assist you in finding the Minimum Supported Rust Version for a crate.

Install

With Cargo from crates.io [latest release]:

cargo install cargo-msrv to install or
cargo install cargo-msrv --force to update

With Cargo from Github [latest development version]:

cargo install cargo-msrv --git https://github.com/foresterre/cargo-msrv.git --branch main

From the AUR (Arch Linux):

paru -S cargo-msrv

Preview

cargo-msrv preview

Usage

cargo msrv to find the MSRV for the current working directory cargo project.
cargo msrv --path <dir> to find the MSRV in the <dir> directory cargo project.
cargo msrv -- <command> to use <command> as the compatibility check which decides whether a Rust version is compatible or not. This command should be runnable through rustup run <toolchain> <command>.
cargo msrv --verify to verify the MSRV, if defined with the 'package.metadata.msrv' key in the 'Cargo.toml'.

Options: ``` cargo-msrv Helps with finding the Minimal Supported Rust Version (MSRV)

USAGE: cargo msrv [OPTIONS]

OPTIONS: --bisect Use a binary search to find the MSRV instead of a linear search

-h, --help
        Prints help information

    --include-all-patch-releases
        Include all patch releases, instead of only the last

    --ignore-lockfile
        Temporarily removes the lockfile, so it will not interfere with the building process. This is important when
        testing against Rust versions prior to 1.38.0, for which Cargo does not recognize the new v2 lockfile.
    --max <max>
        Latest (most recent) version to take into account.Version must match a valid Rust toolchain, and be semver
        compatible. [aliases: maximum]
    --min <min>
        Earliest (least recent) version to take into account. Version must match a valid Rust toolchain, and be
        semver compatible. Edition aliases may also be used. [aliases: minimum]
    --no-log
        Disable logging

    --no-read-min-edition
        If provided, the 'package.edition' value in the Cargo.toml will not be used to reduce search space.

    --output-format <output_format>
        Output status messages in machine-readable format. Machine-readable status updates will be printed in the
        requested format to stdout. [possible values: json]
    --release-source <release_source>
        Select the rust-releases source to use as the release index [default: rust-changelog]  [possible
        values: rust-changelog, rust-dist]
    --path <DIR>
        Path to the cargo project directory

    --target <TARGET>
        Check against a custom target (instead of the rustup default)

    --toolchain-file
        Output a rust-toolchain file with the MSRV as toolchain. The toolchain file will pin the Rust version for
        this crate. See https://rust-lang.github.io/rustup/overrides.html#the-toolchain-file for more.
-V, --version
        Prints version information

    --verify
        Verify the MSRV defined in the 'package.rust-version' or the 'package.metadata.msrv' key in Cargo.toml. When
        this flag is present, cargo-msrv will not attempt to determine the true MSRV. Instead it attempts to verify
        whether for the specified MSRV, the `check` command passes. This is similar to how we determine whether a
        Rust toolchain version is compatible for your crate or not.

ARGS: ... If given, this command is used to validate if a Rust version is compatible. Should be available to rustup, i.e. the command should work like so: rustup run <toolchain> <COMMAND>. The default check action is cargo check --all.

An argument provided after two dashes (--), will be interpreted as a custom command check command, used to validate whether a Rust toolchain version is compatible. The default check command is "cargo build". A custom check command should be runnable by rustup, as they will be passed on to rustup like so: rustup run <toolchain> <COMMAND...>. You'll only need to provide the

JSON format

There are 6 types of status messages, each type is indicated by the reason key.

Report mode

Reports the mode which will be used by cargo-msrv. There are currently two modes: determine-msrv and verify-msrv, which respectively

jsonc { "reason": "mode", // The mode in which cargo-msrv will operate "mode": "determine-msrv" /* OR */ "mode": "verify-msrv", // The toolchain that will be used "toolchain":"x86_64-unknown-linux-gnu", // command used to check a version "check_cmd":"cargo check --all"} }

Installing and Checking

Reported when a toolchain will be installed, or when a toolchain will be run to check whether the version of the toolchain is compatible.

jsonc { "reason": "installing", /* OR */ "reason": "checking", // The current version being installed or checked "version": "1.25.0", // The number of versions checked before this "step": 0, // The total number of versions to be checked "total": 55, // The toolchain that is being used "toolchain": "x86_64-unknown-linux-gnu", // The command used to check each version "check_cmd": "cargo check --all" }

Check complete

Reported when a check, which determines whether the toolchain version under test is compatible, completes.

jsonc { "reason": "check-complete", // The version that was just checked "version": "1.25.0", // The number of versions checked before this "step": 0, // The total number of versions to be checked "total": 55, // true if this version is supported "success": false, // The toolchain that is being used "toolchain": "x86_64-unknown-linux-gnu", // The command used to check each version "check_cmd": "cargo check --all" }

MSRV completed

Reported when all actions for a mode have been run to completion.

jsonc { "reason": "msrv-complete" /* OR */ "reason": "verify-complete", // true if a msrv was found "success": true, // the msrv if found. The key will be absent if msrv wasn't found "msrv": "1.42.0", // The toolchain that is being used "toolchain": "x86_64-unknown-linux-gnu", // The command used to check each version "check_cmd": "cargo check --all" }

Testing

Tests should be run with a single thread, because otherwise rustup uses the a single place for the download cache of a specific toolchain version, and our multiple tests may attempt to overwrite or move the same cached version causing the tests to get stuck and fail. You can achieve the above with the following Cargo command: cargo test -- --test-threads=1.

License

Licensed under either of

Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

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.