Only include JAR files in lib in the unmanaged classpath.

project/SparkBuild.scala

@@ -19,7 +19,7 @@ object SparkBuild extends Build {
     version := "0.4-SNAPSHOT",
     scalaVersion := "2.9.0-1",
     scalacOptions := Seq(/*"-deprecation",*/ "-unchecked", "-optimize"), // -deprecation is too noisy due to usage of old Hadoop API, enable it once that's no longer an issue
-    unmanagedJars in Compile <<= baseDirectory map { base => (base ** "*.jar").classpath },
+    unmanagedJars in Compile <<= baseDirectory map { base => (base / "lib" ** "*.jar").classpath },
     retrieveManaged := true,
     transitiveClassifiers in Scope.GlobalScope := Seq("sources"),
     testListeners <<= target.map(t => Seq(new eu.henkelmann.sbt.JUnitXmlTestsListener(t.getAbsolutePath))),