What does "'revision 2' should be removed" mean in brew audit?

We want to bump the revision of a formula to re-trigger a reinstallation (since ffmpeg sometimes has issues with x264 or x265 being bumped, but then ffmpeg won’t find their shared libraries).

This is the diff: https://github.com/homebrew-ffmpeg/homebrew-ffmpeg/pull/21/files

The Travis build fails in the brew audit stage with:

  * 'revision 2' should be removed
Error: 1 problem in 1 formula detected
The command "brew audit --except=file,specs $TRAVIS_REPO_SLUG/ffmpeg" exited with 1.

What does this mean? Why should it be removed if we’re not actually releasing a new version?

Since it doesn’t happen on user machines I suspect it’s an issue in with the git base in travis.

Can you please clarify what you mean by “git base”? Does Travis not check out the most recent HEAD of the repo and Homebrew-core?