error: newSource1.scala:4: Symbol 'type stuberrors.A' is missing from the classpath. This symbol is required by 'type stuberrors.B.D'. Make sure that type A is in your classpath and check for conflicting dependencies with `-Ylog-classpath`. A full rebuild may help if 'B.class' was compiled against an incompatible version of stuberrors. println(new B) ^