import scala.reflect.runtime.universe.TypeTag
import scala.annotation.implicitNotFound

@implicitNotFound("Sorry, type inference was unable to figure out the type. You need to provide it explicitly.")
trait NotNothing[T]

object NotNothing {
  private val evidence: NotNothing[Any] = new Object with NotNothing[Any]

  implicit def notNothingEvidence[T](implicit n: T =:= T): NotNothing[T] =
    evidence.asInstanceOf[NotNothing[T]]
}

def inject[T](implicit tt: TypeTag[T], nn: NotNothing[T]) =
  tt.toString

inject
// <console>:12: error: Sorry, type inference was unable to figure out the type. You need to provide it explicitly.
//               inject
//               ^

inject[Nothing]
// <console>:12: error: Sorry, type inference was unable to figure out the type. You need to provide it explicitly.
//               inject[Nothing]
//                     ^

val foo: String = inject
// <console>:11: error: Sorry, type inference was unable to figure out the type. You need to provide it explicitly.
//       val foo: String = inject
//                         ^

inject[String]
// res6: String = TypeTag[String]

inject[Int]
// res7: String = TypeTag[Int]