builder > A.scala B.scala compiling Set(A.scala, B.scala) Changes: Map() builder > A.scala compiling Set(A.scala) Changes: Map(object A -> List(Changed(Definition(A.x))[method x changed from (zz: Int, yy: Int)Int to (yy: Int, zz: Int)Int flags: ])) invalidate B.scala because it references changed definition [Changed(Definition(A.x))[method x changed from (zz: Int, yy: Int)Int to (yy: Int, zz: Int)Int flags: ]] compiling Set(B.scala) Changes: Map(object B -> List())