FAQ

Can clippy enforce Google’s Rust style guide?

Partly. Clippy, rustfmt and cargo-deny together enforce 32 of the guide’s 62 in-scope rules, fully or partially, with 41 lints and three config files. The other 30 rules are design judgment, such as newtype or type alias and iterator or Vec, which no linter can decide. The kit covers those with AGENTS.md for coding agents and a human review guide. The coverage table lists every rule and what enforces it.

Which rules can’t be linted?

About 30 judgment rules: library versus application API choices, newtypes versus aliases, named fields versus tuples, iterators versus Vec in signatures, generics versus dyn Trait, naming of lifetimes, generics and abbreviations, getters and setters, macros, and how much type inference is too much. Why not explains each, plus the gaps in lints that are enabled.

How do I adopt it?

Download five files into your project root, append the lint tables to Cargo.toml, and run cargo +nightly fmt, cargo clippy --workspace --all-targets -- -D warnings and cargo deny check bans. The quick start has copyable commands for single crates and workspaces and takes about five minutes.

How do I make Claude Code, Codex or Cursor follow it?

Put the kit’s AGENTS.md at your repository root. Codex, Cursor, Gemini CLI, GitHub Copilot and most other agents read it automatically; for Claude Code, run ln -s AGENTS.md CLAUDE.md. It tells the agent which commands to run before finishing, forbids editing the lint configuration to silence warnings, and lists the judgment rules with examples. The quick start also has a one-prompt setup you can paste into any agent.

Does it work on stable Rust?

Yes. The lints, clippy configuration and cargo-deny run on stable Rust 1.95 or newer. Three of the guide’s rustfmt options (imports_granularity, hex_literal_case, format_macro_matchers) exist only on nightly rustfmt, so run cargo +nightly fmt to apply them. Stable rustfmt prints a warning and applies everything else.

What happens with an existing codebase?

Expect many warnings at first. Format in one commit, run cargo clippy --fix for the auto-fixable lints, then defer the noisy lints explicitly and re-enable them one by one. Adopting in depth has the step-by-step rollout, including how to protect a published library’s API.

What if the guide allows an exception?

Keep the lint on and record the exception where it happens: #[expect(clippy::exhaustive_structs, reason = "options struct; callers use struct update syntax")]. A suppression without a reason fails the build, and #[expect] fails once it is no longer needed. The human review guide lists which reasons the guide accepts for each lint.

Is this official?

No. It is an unofficial community project, not affiliated with or endorsed by Google. The Google Rust Style Guide is published by Google under CC-BY 3.0; this kit paraphrases its rules, links to the original sections, and is licensed Apache-2.0.

How do I remove it?

Revert the commit that added it, or run the removal script in the quick start. The script deletes only config files that are still identical to the kit’s versions, so your own files are never touched. Then remove the lint tables from Cargo.toml.

How is the kit kept correct?

Its CI proves the configuration on every push and weekly against the latest stable clippy. A fixture crate of deliberate violations must trigger exactly the expected 45 lints, a rustfmt fixture must format to an expected file, and cargo-deny must reject a crate that depends on ctor. See how it works.