Possible issue: reviewdog/action-golangci-lint does not report findings and does not fail CI

[y-soliloquy]

Summary

Hi.

golangci-lint correctly detects issues, but reviewdog does not create any PR reports/comments in any filter_mode.

• In nofilter, reviewdog prints all lint results to the GitHub Actions log
  and CI fails, but still no PR comments are created.

• In all other filter modes (added, diff_context, file):

  • CI does not fail
  • reviewdog produces no output
  • reviewdog creates no PR comments

My expected behavior is:

• In filter_mode: added, reviewdog reports only issues on added/modified lines.
• Reviewdog creates PR comments (github-pr-review).
• CI fails when lint errors exist on added/modified lines.

Currently none of these behaviors work.

This is not a permissions issue — my workflow explicitly grants:
https://docs.github.com/en/actions/reference/workflows-and-actions/workflow-syntax#permissions

permissions:
  checks: write
  contents: read
  pull-requests: write

Repository structure (simplified):

repo-root/
  .golangci.yml
  app/
    go.mod

Workflow:

- uses: reviewdog/action-golangci-lint@v2.8.0
  with:
    github_token: ${{ secrets.HOGE_TOKEN }}
    workdir: app
    golangci_lint_flags: "--config=../.golangci.yml ./... --timeout=5m"
    fail_level: warning
    reporter: github-pr-review
    filter_mode: <varies>
    go_version_file: app/go.mod

Reference for filter_mode:
https://github.com/reviewdog/action-golangci-lint?tab=readme-ov-file#filter_mode

---

Behavior of each filter_mode

filter_mode: added

• CI does not fail
• No PR reports
• No lint issues detected

log (simplified)

Running golangci-lint...
  31 issues:
  * errcheck: 11
  * gocognit: 1
  * gocritic: 1
  * gofmt: 3
  * prealloc: 1
  * staticcheck: 7
  * unparam: 1
  * usetesting: 5
  * whitespace: 1
Running reviewdog 🐶 ...
  /home/runner/work/_temp/reviewdog-iCwcu0/reviewdog -f=golangci-lint -name=golangci -reporter=github-pr-review -filter-mode=added -fail-level=warning -fail-on-error=false -level=error

filter_mode: diff_context

• CI does not fail
• No PR reports
• No lint issues detected

The logs are almost identical to the ones shown in the filter_mode: added case, except for the filter_mode value.

filter_mode: file

• CI does not fail
• No PR reports
• No lint issues detected

The logs are almost identical to the ones shown in the filter_mode: added case, except for the filter_mode value.

filter_mode: nofilter

• CI fails (expected)
• Still no PR reports
• reviewdog logs show all lint issues
• Warning about “too many annotations” appears
• No PR reports created

---

Conclusion

• golangci-lint itself works correctly.
• reviewdog does not generate PR reports/comments for any filter_mode in this repository layout (Go module under app/).
• Only nofilter shows lint output, but still does not produce PR comments.
• It seems like reviewdog may be failing to match file paths against PR diffs, causing all non-nofilter modes to drop results.
• If there's any additional information I can provide, I'm happy to help debug this!
• I want to use filter_mode: added.