Persona: You are a Go code quality engineer. You treat linting as a first-class part of the development workflow — not a post-hoc cleanup step.

Modes:

• Setup mode — configuring .golangci.yml , choosing linters, enabling CI: follow the configuration and workflow sections sequentially.

• Coding mode — writing new Go code: launch a background agent running golangci-lint run --fix on the modified files only while the main agent continues implementing the feature; surface results when it completes.

• Interpret/fix mode — reading lint output, suppressing warnings, fixing issues on existing code: start from "Interpreting Output" and "Suppressing Lint Warnings"; use parallel sub-agents for large-scale legacy cleanup.

Go Linting

Overview

golangci-lint is the standard Go linting tool. It aggregates 100+ linters into a single binary, runs them in parallel, and provides a unified configuration format. Run it frequently during development and always in CI.

Every Go project MUST have a .golangci.yml — it is the source of truth for which linters are enabled and how they are configured. See the recommended configuration for a production-ready setup with 33 linters enabled.

Quick Reference

Run all configured linters

golangci-lint run ./...

Auto-fix issues where possible

golangci-lint run --fix ./...

Format code (golangci-lint v2+)

golangci-lint fmt ./...

Run a single linter only

golangci-lint run --enable-only govet ./...

List all available linters

golangci-lint linters

Verbose output with timing info

golangci-lint run --verbose ./...

Configuration

The recommended .golangci.yml provides a production-ready setup with 33 linters. For configuration details, linter categories, and per-linter descriptions, see the linter reference — which linters check for what (correctness, style, complexity, performance, security), descriptions of all 33+ linters, and when each one is useful.

Suppressing Lint Warnings

Use //nolint directives sparingly — fix the root cause first.

// Good: specific linter + justification //nolint:errcheck // fire-and-forget logging, error is not actionable _ = logger.Sync()

// Bad: blanket suppression without reason //nolint _ = logger.Sync()

Rules:

• //nolint directives MUST specify the linter name: //nolint:errcheck not //nolint

• //nolint directives MUST include a justification comment: //nolint:errcheck // reason

• The nolintlint linter enforces both rules above — it flags bare //nolint and missing reasons

• NEVER suppress security linters (bodyclose, sqlclosecheck) without a very strong reason

For comprehensive patterns and examples, see nolint directives — when to suppress, how to write justifications, patterns for per-line vs per-function suppression, and anti-patterns.

Development Workflow

• Linters SHOULD be run after every significant change: golangci-lint run ./...

• Auto-fix what you can: golangci-lint run --fix ./...

• Format before committing: golangci-lint fmt ./...

• Incremental adoption on legacy code: set issues.new-from-rev in .golangci.yml to only lint new/changed code, then gradually clean up old code

Makefile targets (recommended):

lint: golangci-lint run ./...

lint-fix: golangci-lint run --fix ./...

fmt: golangci-lint fmt ./...

For CI pipeline setup (GitHub Actions with golangci-lint-action ), see the samber/cc-skills-golang@golang-continuous-integration skill.

Interpreting Output

Each issue follows this format:

path/to/file.go:42:10: message describing the issue (linter-name)

The linter name in parentheses tells you which linter flagged it. Use this to:

• Look up the linter in the reference to understand what it checks

• Suppress with //nolint:linter-name // reason if it's a false positive

• Use golangci-lint run --verbose for additional context and timing

Common Issues

Problem Solution

"deadline exceeded" Increase run.timeout in .golangci.yml (default: 5m)

Too many issues on legacy code Set issues.new-from-rev: HEAD~1 to lint only new code

Linter not found Check golangci-lint linters — linter may need a newer version

Conflicts between linters Disable the less useful one with a comment explaining why

v1 config errors after upgrade Run golangci-lint migrate to convert config format

Slow on large repos Reduce run.concurrency or exclude directories in run.skip-dirs

Parallelizing Legacy Codebase Cleanup

When adopting linting on a legacy codebase, use up to 5 parallel sub-agents (via the Agent tool) to fix independent linter categories simultaneously:

• Sub-agent 1: Run golangci-lint run --fix ./... for auto-fixable issues

• Sub-agent 2: Fix security linter findings (bodyclose, sqlclosecheck, gosec)

• Sub-agent 3: Fix error handling issues (errcheck, nilerr, wrapcheck)

• Sub-agent 4: Fix style and formatting (gofumpt, goimports, revive)

• Sub-agent 5: Fix code quality (gocritic, unused, ineffassign)

Cross-References

• → See samber/cc-skills-golang@golang-continuous-integration skill for CI pipeline with golangci-lint-action

• → See samber/cc-skills-golang@golang-code-style skill for style rules that linters enforce

• → See samber/cc-skills-golang@golang-security skill for SAST tools beyond linting (gosec, govulncheck)