errcopy := string([]byte(err))
	sys2()
	if err != errcopy {
		t.Errorf("syscall.%s error string changed from %q to %q\n", fn, errcopy, err)
	}
}

// issue 13770: errors cannot be nested in Plan 9

func TestPlan9Syserr(t *testing.T) {
	testalias(t,
		"Syscall",
		func() error {
			return syscall.Mkdir("/", 0)
		},
		func() error {
			return syscall.Mkdir("#", 0)
		})
	testalias(t,
		"Syscall6",
		func() error {