Avoid the Eclipse "managed build" trap at all costs
I implore you, if you want any kind of future-proofing of your development system do not resort to using the Eclipse “managed build” setup. At first it might seem the obvious step, to get your IDE to deal with what should and shouldn’t be included in your final product, because you’re already working in there, right?
And then you discover that you can’t really debug how it builds your binaries. You get inscrutable “internal failure” messages with nothing more to go on. There is no extra level of debug, no graph of dependencies to illustrate what is happening.
If you want to run a continuous integration server — and you do, don’t you? — you’ll notice that “headless Eclipse” is a monstrosity that shouldn’t have been let loose by right-thinking people. Have you read any HP Lovecraft, by any chance?
In short, you have no control over what happens to your build any more. You press the little button in the GUI and hope it makes the right decisions. In my experience, that seems quite naive.