builder > A.scala B.scala
compiling Set(A.scala, B.scala)
Changes: Map()
builder > A.scala
compiling Set(A.scala)
Changes: Map(class A -> List(Changed(Class(A))[ tparams: List((type T,type T))], Changed(Definition(A.<init>))[constructor A changed from ()A[T] to ()A[T] flags: <method> <triedcooking>]))
invalidate B.scala because it references changed class [Changed(Class(A))[ tparams: List((type T,type T))]]
compiling Set(B.scala)
B.scala:2: error: type mismatch;
 found   : A[Int]
 required: A[Any]
Note: Int <: Any, but class A is invariant in type T.
You may wish to define T as +T instead. (SLS 4.5)
  val a: A[Any] = new A[Int]
                  ^