Why is dependency cache located under project root on Jenkins?

Thanks. They actually pose a potential problem using a global cache. So maybe its best to use a local to the workspace and then configure:

configurations.all {
    resolutionStrategy {
      cacheDynamicVersionsFor 0, 'seconds'
      cacheChangingModulesFor 0, 'seconds'
    }
  }

this should clean up the caches folder right?