Ok, no I see... that makes it a bit clearer. But still there is a small problem with this. Maybe no a bug but more of a feature character. If I, as in my case, wants to apply buildr on an already existing project this will cause a failure initially. I will try to explain:
If you have an already existing project including two separate projects where foo-impl depends on foo-api. The name of the projects are by default in eclipse the same as the folder name in the file system path. When you later try to apply buildr on this project you want add these two project in to a parent (called buildr-bug) so that they can reference each other. After running buildr eclipse the symbolic project name will change to <parent project name>-<child project name>, in my example buildr-bug-foo-api and buildr-bug-foo-impl. The foo-impl project will therefore reference the foo-api project with the symbolic name, buildr-bug-foo-api. This is where it goes wrong. The project name in eclipse wont update to the new symbolic name and the project references will fail since eclipse will not find any buildr-bug-foo-api project.
To work arond this I had to remove the projects from eclispse and import them again. This will forece eclipse to reload the project with their new names.
I'll upload a new example project for you to try out including a buildfile. The project is setup as a non-buildr project and the buildfile should be run to on this non-buildr project to "convert" it to a buildr-project.
I will also attach two screendumps showing the Java Build Path before and after running buildr eclipse.