if exit == 1 {
		if err == nil {
			log.Fatal("stressExec: unexpected exec success")
		}
		return
	}
	if err != nil {
		log.Fatalf("stressExec: exec failure: %v: %s", err, out)
	}
	wantOutput += "\n"
	if string(out) != wantOutput {
		log.Fatalf("stressExec: exec output = %q; want %q", out, wantOutput)
	}
	Println("did exec")
}

func stressExec() {
	gate := make(chan bool, 10) // max execs at once