func BenchmarkStackLeak(b *testing.B) {
    done := make(chan bool, 1)
    for i := 0; i < b.N; i++ {
        go func() {
            growStack(rand.Intn(100))
            done <- true
        }()
        <-done
    }
}

func growStack(i int) {
    if i == 0 {
        return
    }
    growStack(i - 1)
}