raceAll.scala

def raceAll[F[_], E, A](fs: List[F[A]])(implicit F: GenConcurrent[F, E]): F[A] =
  F.deferred[Outcome[F, E, A]] flatMap { d =>
    F uncancelable { poll =>
      val fibersF = fs traverse { fa =>
        fa.guaranteeCase(d.complete(_).void).start
      }

      fibersF flatMap { fibers =>
        poll(d.get.guarantee(fibers.parTraverse_(_.cancel)).flatMap(_.embedNever))
      }
    }
  }