DR-006-Infra: Clippy Integration via rules_lint#

  • Date: 2026-01-19

Clippy Integration via rules_lint
status: accepted
context: Infrastructure
decision: Use rules_lint for Clippy in S-CORE modules
dec_rec__infra__clippy_rules_lint
Decision Record

1. Context / Problem#

S-CORE needs a consistent, Bazel-native way to run Rust Clippy across modules. We initially aligned on rules_rust for Clippy integration, but rules_lint added native Clippy support while that work was ongoing. We must choose one approach to reduce divergence and keep lint workflows maintainable.

Key constraints:

  • Avoid running Clippy across the entire tree by default.

  • Avoid maintaining long, manual target lists.

  • Keep lint rules centralized and versioned.

  • Allow CI-friendly lint runs without additional tooling requirements.

2. Decision#

We adopt rules_lint for Clippy integration in S-CORE modules.

3. Rationale#

rules_lint fits better with the linting workflow:

  • It is designed for linting (output groups, lint tests, lint-oriented UX).

  • It avoids whole-tree runs and manual target lists by linting only the build graph of requested targets.

  • Clippy support is released and tested, which reduces risk.

rules_rust remains a valid option, but it requires manual target enumeration for lint-only runs and is harder to scope for incremental linting.

4. Integration Approach#

Each module integrates Clippy through a rules_lint aspect:

  • Use the shared aspect from @score_rust_policies//clippy:linters.bzl (repo-local aspects remain an option if needed).

  • Reference the centralized Clippy configuration from the policies repo: @score_rust_policies//clippy/strict:clippy.toml.

  • Enable the aspect in .bazelrc via build --aspects=...%clippy and request output groups rules_lint_human (and optionally rules_lint_machine).

  • Skip linting for specific targets using the no-lint tag.

  • For CI, add --@aspect_rules_lint//lint:fail_on_violation=true to fail on findings.

  • Use aspect_rules_lint >= 2.0.0-rc0 to support fail_on_violation with Clippy.

This keeps configuration and behavior consistent while allowing each module to scope linting to the targets it builds.

5. Consequences#

  • Clippy runs on the Rust targets in the build graph of the requested Bazel targets, not the whole repository by default.

  • Lint rules are centralized in score_rust_policies, reducing duplication and drift.

  • The Aspect CLI is not required for Clippy execution; standard bazel build works.

  • rules_lint uses Aspect telemetry; this can be disabled via repo environment variables if required by policy.

6. Future Considerations#

We may integrate the Aspect CLI in the future to enable the bazel lint command and additional lint UX (interactive output, filtering, reporting). This is optional and separate from the Bazel-based execution path.