The output from javadoc has become non deterministic which makes comparing output from consecutive runs difficult. This is a problem when making changes to the build (and I would assume, the javadoc tool itself) and you want to verify that the output didn't change.

The non determinism applies to lists of module names in files called api/$MODULE-summary.html. Attaching two example files that differ, built from the same sources, on the same machine, right after each other with no code changes.

I would suggest sorting the modules in these lists as it would also improve readability.