I have a workspace containing several different apps and a common library project that I am looking to convert from Eclipse to Android Studio and from Ant to Gradle. Curren
Well, Gradle Android plugin simply can't build the debug version of dependent library modules. This is a well-known, old issue and this is not resolved yet.
You can try to use some workarounds from the discussion I mentioned, specifically take a look at posts #35 and #38.