In the past I have been repeatedly discouraged by the difficulty of successfully importing projects into eclipse. Despite its high publicity and good reputation, I never bothered learning it, until now. In my current job I have to read massive amount of code organized into projects and modules. It becomes impossible to navigate with a simple text editor like macvim.
Barring some version incompatibilities, following instructions on how to setup eclipse and load a project directory is relatively simple, with plenty of tutorials on the web. It becomes a nightmare, however, when you try to be creative and say open up two projects at the same time, without exerting the utmost care. This happens when I try to load a python project (sage) right after loading a java project. Probably I should have closed the first one before proceeding, but I thought eclipse would be smart enough to let me undo certain operations. It turns out certain things are not reversible after all. After hours of plowing through internet forums, I decided that the best course of action is to do manual deletion and file modification, instead of relying on GUI.
So the first step is to open up the file eclipse -> configuration -> org.eclipse.ui.ide.prefs and delete the workspace name under RECENT_WORKSPACE. This causes eclipse to forget that particular directory so it won’t try to over-analyze when two projects are loaded simultaneously by accident.
Earlier I tried removing the entire directory of .metadata under my project directory. This doesn’t quite do the trick because eclipse is so protective of your work history that it regenerates this folder for you every time you load the workspace. So do the first one and be happy:)