the proguardInJars task gets all jars from the dependency classpath which includes all managed and unmanaged dependencies in Compile (good) as well as all dependencies for other configs than compile (bad). E.g. the test config (which for example pulls in scalaz from specs) and all sbt plugins like sbteclipse.
IMHO proguardInJars should solely include managed and unmanaged dependencies in Compile and not on dependency-classpath so it does not include sbt plugins, test frameworks and other stuff you definitely don't want in your proguarded jar.
thank you