Download this and run with ammonite

akka_streams_pitfalls_1.sc

#!/usr/bin/env amm
import $ivy.`com.typesafe.akka::akka-stream:2.5.4`

import akka.Done
import akka.stream._
import akka.stream.scaladsl._
import scala.concurrent.Future
import scala.concurrent.ExecutionContext.Implicits.global
import scala.concurrent.duration._

implicit val as = akka.actor.ActorSystem()
implicit val m = ActorMaterializer()

val result: Future[Done] = Source(1 to 10)
 .map(_ / 0)
 .runWith(Sink.ignore)

result.onComplete { result =>
  println(s"Result was ${result}")
}