We recently removed the Eclipse-specific files within our Git repository. See MODE-1125 for details.
While this is a good thing overall and generally considered a best-practice, these change may very well cause some problems for existing developers that use Eclipse: when pulling the changes from the upstream repository, Git also removes the Eclipse-specific files from your local file system, which breaks Eclipse.
To fix this locally, perform the following steps within Eclipse:
If you have warnings on the 'modeshape-graph', 'modeshape-jcr-api' and 'modeshape-jcr' projects saying something like:
Build path specifies execution environment J2SE-1.5. There are no JREs installed in the workspace that are strictly compatible with this environment.
then you don't have JDK 1.5 installed. You can either install one, ignore those warnings in your Problems view, or edit the project properties for each of those 3 projects, choose "Java Build Path", remove the "JRE System Library", choose "Add Library...", and pick the right JRE.
Finally, outside of Eclipse, run 'git status' at the command line to make sure Git is okay. If Git reports that there are a lot of "bin" directories that are untracked, you can simply remove them (as they were created by Eclipse during the Maven import and will not be used). Just remember that we do have a "bin" folder at the top-level of our code containing the release scripts; if you accidentally delete that folder, simply use 'git checkout -- bin/'.
I sincerely apologize for this pain. This was not something we anticipated would happen, but is a one-time thing that we'll have to deal with if we are going to remove the Eclipse-specific files from our source code.
If you run into any problems, please reply here or get on IRC (#modeshape on freenode.net) and ask for help!