ktlint check failed: lint errors in kotlin PR

TL;DR

ktlint found style violations (indentation, imports, spacing). Run ktlint --format on the changed files to auto-fix what it can, then fix the remaining reported violations by hand.

Error

src/main/kotlin/com/acme/Api.kt:27:1: Unexpected indentation (4) (should be 8) (indent)

Steps

1. Reproduce locally: run ./gradlew ktlintCheck or ktlint "src/**/*.kt". Expected: the same violation list CI shows.
2. Auto-fix: run ktlint --format "src/**/*.kt" (or ./gradlew ktlintFormat). Expected: formatting violations like indentation and import order disappear.
3. Fix the rest manually: read each remaining rule message (e.g. no-wildcard-imports) and adjust the code. Expected: no violations remain.
4. Re-run the check. Expected: BUILD SUCCESSFUL / no findings, and the PR gate passes.

When to use

• ktlint (CLI or Gradle plugin) reports style violations and fails the PR.
• The violations are formatting/style, not design.

When not to use

• detekt reports complexity or code-smell issues - that is a different tool with different fixes.
• The build itself fails to compile; fix compilation first.

Tool compatibility

• ktlint 0.50+ / Gradle ktlint plugin.
• Kotlin 1.8+.

Variant phrasings

ktlint fails only in CI, passes locally

Version drift: pin the same ktlint version in CI and locally.

Too many violations to fix at once

Run the formatter first; it typically clears the majority automatically.

Why it happens

ktlint enforces the official Kotlin code style. The check task fails the build on any violation, so unformatted code blocks the PR even when tests pass.

Edge cases

• --format rewrites files; review the diff before committing - it occasionally reformats in surprising ways.
• Baseline files can grandfather existing violations while new code stays clean.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_ldRKHLfvuwgVkxpz3LOJ8Q