error: newSource1.scala:13: Symbol 'type stuberrors.A' is missing from the classpath.
This symbol is required by 'class stuberrors.D'.
Make sure that type A is in your classpath and check for conflicting dependencies with `-Ylog-classpath`.
A full rebuild may help if 'D.class' was compiled against an incompatible version of stuberrors.
      b.foo[D]
            ^
error: newSource1.scala:13: type arguments [stuberrors.D] do not conform to method foo's type parameter bounds [T <: stuberrors.A]
      b.foo[D]
           ^
error: newSource1.scala:13: Symbol 'type stuberrors.A' is missing from the classpath.
This symbol is required by 'type stuberrors.B.T'.
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.
      b.foo[D]
      ^