- Blow away all your code (just for fun, mostly).
- If you weren't using source control, what the hell is wrong with you?
- Delete all your packages in Eclipse - (moderately satisfying)
- Blow away project properties directory called project (not sure if this is strictly necessary but it feels terrific)
- Pull a clean copy of your code and everyone else's
- Start over. Run ./sbt nars eclipse - or whatever. File->Import->General->Existing Projects into Workspace
I find this usually does the trick, but would appreciate thoughts from an expert on why it should be this hard. Thanks to Dan Glaser by the way.