[BUG] rdjson formatting always fails

[SavePointSam]

Is there an existing issue for this?

• [x] I have searched the existing issues

Does this issue exist in the latest version?

• [x] I'm using the latest release

Describe the bug?

While trying to integrate this action into our workflow, I've been unable to get linting annotations to function. If I disable annotations, I see the expected ESLint errors in the console. However, once reviewdog is involved, everything fails with the following message. I've tried tracking down what this issue is and tried a variety of different configurations to bypass the issue, but am unable to.

reviewdog: parse error: failed to unmarshal rdjson (DiagnosticResult): proto: syntax error (line 1:1): unexpected token [

Our current configuration:

jobs:
  validate-app:
    # ...
    steps:
      # ...

      - name: Run ESLint on changed files
        # tj-actions/[email protected]
        uses: tj-actions/eslint-changed-files@0cfcd35949a961d13e964a7c2a4971c0e89b68fc
        with:
          config_path: "eslint.config.mjs"

{
  ...,
  "devDependencies": {
    ...,
    "eslint": "^9.31.0",
  }
}

We are also using the latest "flat" configuration style from ESLint

To Reproduce

Setup new project utilizing latest ESLint and latest release of this action. Run with at least one known linting error and annotations disabled. See expected error output. Run again with annotations enabled, see rdjson formatting fail and cause reviewdog to crash.

What OS are you seeing the problem on?

ubuntu-latest or ubuntu-22.04

Expected behavior?

Linting annotations to work as expected from examples in README.

Relevant log output

eslint-changed-files
  Resolving repository path: /home/runner/work/XXXXX/XXXXX/.
  Running ESLint on changed files...
  reviewdog: parse error: failed to unmarshal rdjson (DiagnosticResult): proto: syntax error (line 1:1): unexpected token [
  Error: Error running eslint.
Error: Process completed with exit code 1.

Has all relevant logs been included?

• [x] I've included all relevant logs

Anything else?

No response

Code of Conduct

• [x] I agree to follow this project's Code of Conduct