exception during macro expansion: java.util.NoSuchElementException: head of empty list

[cerveada]

Using automapper version 0.6.2

import io.bfil.automapper._

case class Inner(x: Int)


case class Foo(in: Inner)
case class Bar(in: Option[Inner])

automap(Foo(Inner(42))).to[Bar]

exception during macro expansion:
java.util.NoSuchElementException: head of empty list
at scala.collection.immutable.Nil$.head(List.scala:469)
at scala.collection.immutable.Nil$.head(List.scala:466)
at io.bfil.automapper.Mapping$.io$bfil$automapper$Mapping$$getFirstTypeParam$1(Mapping.scala:61)
at io.bfil.automapper.Mapping$.$anonfun$generateMapping$3(Mapping.scala:126)
at scala.collection.immutable.List.map(List.scala:293)
at io.bfil.automapper.Mapping$.extractParams$1(Mapping.scala:100)
at io.bfil.automapper.Mapping$.generateMapping(Mapping.scala:161)
at io.bfil.automapper.Mapping$.materializeMappingImpl(Mapping.scala:14)
automap(Foo(Inner(42))).to[Bar]

I can add the implicit mapping between Option[Inner] and Inner, but it doesn't change anything the error still happens.