No, it is not for scala. 
This repo is specified in cascading/pom.xml. 
When I built locally, it worked find without this, but CI build on github failed, complaining about being unable to resolve dependencies like cascading-core-2.5.0-wip-77 for some reason, even though scalding module doesn't even depend on those directly, so I panicked, and added the same repo here as in cascading/pom.xml