def onShutdown[T](t: => T, s: fs2.Stream[IO, T]) =
    fs2.Stream.eval {
      Deferred[IO, Unit] flatMap { shutdownInitiated =>
        Deferred[IO, Unit] map { streamFinished =>
          val sd = IO {
            sys.addShutdownHook {
              shutdownInitiated.complete().unsafeRunSync()
              streamFinished.get.unsafeRunSync()
            }
          }
          val poison = fs2.Stream.bracket(sd >> shutdownInitiated.get)(_ => IO.unit) >> fs2.Stream(Some(t), None)
          poison.merge(s.map(t => Some(t))).unNoneTerminate onFinalize {
            streamFinished.complete()
          }
        }
      }
    } flatten