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Cargo Tool

New in version 3.0.

The Cargo Tool utilizes functionality from the Cargo toolchain to test and check Rust code for errors and suspicious constructs. Bugs and abnormal code constructs detected by this tool can be intercepted before they have shipped to users, preventing crashes and poor performance in production.

Lint checks are performed using cargo clippy, and unit tests are performed using cargo test.

Supported File Types

The following are supported by this tool.

  • Rust: *.rs


Installing Rust and Cargo

This tool requires that Rust/Cargo is installed on the system running the Review Bot worker. Rust/Cargo is available for download on Linux/Mac/Windows.

See the Rust installation guide for instructions.

Installing Clippy

In order to use the linting feature, the Cargo component clippy must be installed and configured. Review Bot currently requires this to be installed even if you don’t intend to use this feature.

To install Clippy, run:

rustup component add clippy

See the Clippy documentation for more information.


Cargo Location

If the cargo command is in a non-standard location, and can’t be found in Review Bot’s PATH environment variable, then you’ll need to specify the path in the Review Bot worker config file:

exe_paths = {
    'cargo': '/path/to/cargo',
    'cargo-clippy': '/path/to/cargo-clippy',

You will need to restart the Review Bot worker after making this change.

Enabling Full Repository Access

This tool requires full repository access, which is available for Git and Mercurial repositories. Each repository you intend to use must be configured in the Review Bot worker config file.

See Full Repository Access for instructions.

Enabling Cargo Tool in Review Board

First, you’ll need to add a Review Bot configuration in Review Board (see Tool Configurations).

The following configuration options are available:

Check and lint code:

Enable this checkbox if you want to perform lint checks on uploaded Rust code.

This will run cargo clippy on the code.

Run tests:

Enable this checkbox if you want to run unit tests on uploaded Rust code.

Note that this can take some time, depending on the size of the codebase.

This will run cargo test on the code.