by far not ideal, but at least something

[info]   scala.invariants.InvariantFailedException: invariant failed:
[info] when verifying !(parents.length != 0 && parents.tail.exists((_.argss.nonEmpty)))
[info] found that parents.length is not equal to 0
[info] and also parents.tail.forall(_.argss.empty) is false
[info] context is Template(List(),List(Parent(Ident(),List(List())), Parent(Ident(),List(List()))),Self(None,None),List())
[info]   at scala.invariants.InvariantFailedException$.raise(Exceptions.scala:13)
[info]   at scala.reflect.Tree$Template.<init>(Trees.scala:196)