By any chance, is it possible to attach the sources of the Scala compiler?
I was just trying out the Scala plugin for IDEA and found that I can easily attach the sources for the Scala standard library (after they're not found, I simply have to click "attach sources" in the upper right and include the path to the sources). The sources directory that I include also contains the Scala compiler sources (I include this dir: https://github.com/scala/scala/tree/v2.10.0-M6/src), however, the compiler subdirectory ends up not being included. Trying to manually include only the Scala compiler source directory results in nothing, no error message, nothing happens, no sources attached. I guess my question is, by what definition is a source directory a "root" directory, and why is it that scala/src/actors or scala/src/library are root directories that are included when I "attach" them, but not scala/src/compiler?