black formatter complains that a file should be formatted but fails to do so

The error message suggests that the reviewdog action is trying to access the is_formatted output of the black formatter action, but the black formatter action does not have an id defined.

To fix this, you need to add an id to the black formatter action, like so:

``` - name: black formatter uses: rickstaa/action-black@v1 id: black_formatter with: black_args: ". --check" ```

Once you have added the id, you can then use it in the reviewdog action, like so:

``` - name: Annotate diff changes using reviewdog if: steps.black_formatter.outputs.is_formatted == 'true' /// black_formatter is the id of the previous step as your example uses: reviewdog/action-suggester@v1 with: tool_name: blackfmt ```