Incidentally, there have been similar space-consuming issues on OS X [1] [2]. Granted, the second one was a third-party application (probably) misusing file versioning APIs, but it's still 200GB of disk space being used in a way that is non-obvious to the owner of the machine.

1. https://apple.stackexchange.com/questions/84784/128gb-ssd-an...

2. https://medium.com/@thomasdegry/how-sketch-took-over-200gb-o...