I did an eclipse import from several eclipse projects and I got an error message dialog box saying that "ECLIPSE" variable not found or something like that... don't remember exactly.
But none of the eclipse project Libraries where imported. So if I go under Project Structure, Module, dependencies, I see the JDK and "ECLIPSE" with a question mark and without any libraries, so the project does not build. I have several eclipse libraries on my original eclipse project, none of then got imported. As a side note, I'm doing eclipse plugin development.