This buildfile is part of projectlombok.org. It responsible for finding, downloading, and updating findbugs. Downloading findbugs v1.3.9 from sourceforge... You don't have the findbugs dependency. If you want to run the 'ant findbugs' task to run findbugs on the lombok sources, you'll need it. Otherwise, you can skip it. If you want me to do so, I will download findbugs now and unpack it in the appropriate place (deps/buildScripts/findbugs). The file will be downloaded from sourceforge. Pick one (first letter will do): Skip - Skips this download. This dependency is optional. Download - Grabs findbugs, so that you can run 'ant findbugs'.