In Cleanup Policy, if "Component Usage" is used on RubyGems repo format, then it is not working correctly as it takes into account <package-version>.gemspec.rz last download date. The `.gem` file haven't been downloaded, while the `.gemspec.rz` was last downloaded today (gemspec files are downloaded every time bundler prepares list of artifacts to download so it shouldn't be taken into account for gem cleanup).
1) Set "Component Usage" to something like 30 days and run preview on ruby gems repo.
2) In my CleanUp preview example tty-color-0.5.1 is showing.
3) Use Browse download tty-color-0.5.1.gemspec.rz from that ruby gems proxy repo.
4) Nexus should show the current status.
tty-color-0.5.1.gemspec.rz last downloaded shows today's date
tty-color-0.5.1.gem last downloaded shows date older than 30 days
5) In same CleanUp preview as in step 2, tty-color-0.5.1 will no longer show in list of components to be deleted
For RubyGems format the last download time for <package-version>.gem file should be taken into account and not the <package-version>.gemspec.rz