[eclipse] Function of Project > Clean in Eclipse

There's another problem at work here. The Clean functionality of Eclipse is broken. If you delete files outside of Eclipse it will not pick up on the fact that the files are now missing, and you'll get build errors until you delete the files manually. Even then, that will not necessarily work either, especially if there are a lot of files missing. This happens to me rather often when I check out a branch of code that has had a lot of changes since the last time I built it. In that case, the only recourse I've found is to start a brand new workspace and reload the project from scratch.