Github user HeartSaVioR commented on the issue:
https://github.com/apache/flink/pull/6256
@zentol First of all, thanks for the reviewing!
The RAT plugin `reads and parses` the .gitignore file like below so adding
it to .gitignore file in root directory is effective. The issue was that it
doesn't apply to .gitignore in each module.
```
[INFO] --- apache-rat-plugin:0.12:check (default) @ flink-parent ---
[INFO] Added 1 additional default licenses.
[INFO] Enabled default license matchers.
[INFO] Added 1 custom approved licenses.
[INFO] Will parse SCM ignores for exclusions...
[INFO] Parsing exclusions from
/Users/jlim/WorkArea/JavaProjects/flink/.gitignore
[INFO] Finished adding exclusions from SCM ignore files.
[INFO] 93 implicit excludes (use -debug for more details).
```
But yes, I agree RAT exclusions are better to set in the plugin
configuration. I will update.
---