reviewdog: annotation failed: line is outside of the diff

TL;DR

The linter reported a finding on a line that git does not consider changed, and reviewdog can only annotate lines inside the diff. The usual cause is drift: the code was reformatted or rebased between the lint run and the diff, or the linter ran on whole files. Rebase onto the current base, re-run the linter on the exact checked-out code, and keep the filter on changed lines. The line numbers have to agree.

The error

reviewdog: annotation failed: line is outside of the diff

Steps

1. Verify the flagged line is outside the diff

Take a failing file and line number from the log, then check the actual diff:

git diff origin/main...HEAD -- path/to/file

Expected output: the flagged line number falls outside every hunk, confirming the mismatch.

2. Check for drift between lint and diff

Look at the job order: does a format step, a rebase, or a generated-code step run between the linter and reviewdog? Any rewrite shifts line numbers. Expected output: you can identify the step that moved the lines.

3. Rebase onto the current base

Update the branch so the diff reviewdog sees matches the code the linter saw:

git fetch origin
git rebase origin/main
git push --force-with-lease

Expected output: a fresh diff with no stale hunks.

4. Re-run the linter on the exact checkout

Run the linter after the final checkout state, not on cached results from an earlier job. Pipe its fresh output straight into reviewdog. Expected output: linter line numbers match the diff hunks.

5. Keep filtering on changed lines

Confirm the reporter uses diff-aware filtering:

reviewdog -filter-mode=diff_context

Expected output: findings on unchanged lines are skipped instead of erroring.

6. Re-run the review step

Expected output: annotations post cleanly with no outside-of-diff errors.

When to use

• reviewdog fails with the line-outside-diff error
• A format or codegen step runs in the same job as the linter
• The PR was rebased while CI was running

When not to use

• Diff parse errors (reviewdog cannot read the diff at all)
• Annotation permission errors
• Linter config or crash problems

Tool compatibility

• reviewdog v0.14 and later
• Any linter piped into reviewdog (eslint, flake8, golangci-lint, and others)
• GitHub check runs and PR review reporters

Variant phrasings

reviewdog cannot annotate line outside diff

Same fix. The mapping between linter output and diff hunks broke.

annotation failed after rebase during CI

The rebase moved the lines mid-run. Re-run the linter after the final rebase.

reviewdog line mapping wrong on generated files

Generated files shift line numbers between generation and lint. Lint the generated output in place.

Why it happens

reviewdog translates each linter finding into a diff position (file plus line inside a hunk). If the linter analyzed different bytes than the diff describes, the position does not exist and the annotation call fails. Anything that rewrites the file between those two moments breaks the mapping.

Edge cases

• Line-ending changes (CRLF to LF) rewrite every line of a file. Normalize line endings before linting.
• Linters that report the end line of a range instead of the start can land one line past a hunk. diff_context filtering absorbs most of these.
• Multi-line findings on single-line hunks: keep the linter output to single-line positions where possible.
• Concurrent pushes to the PR branch during CI: consider concurrency cancellation so a stale run never posts.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_PcA5WU8dXBgqTQCOm3HrrQ