func goexitSeq() Seq[int] {
	return func(yield func(int) bool) {
		runtime.Goexit()
	}
}

func goexitCleanupSeq() Seq[int] {
	return func(yield func(int) bool) {
		for {
			if !yield(55) {
				runtime.Goexit()
			}
		}
	}
}

func TestPull2Goexit(t *testing.T) {
	t.Run("next", func(t *testing.T) {
		var next func() (int, int, bool)
		var stop func()
		if !goexits(t, func() {

	if ns == 0 {
		return scratch
	}
	return ns
}

var goexits = []byte("go: exit ")
var emptystatus = []byte("\x00")
var exiting uint32

func goexitsall(status *byte) {
	var buf [_ERRMAX]byte
	if !atomic.Cas(&exiting, 0, 1) {
		return
	}
	getg().m.locks++
	n := copy(buf[:], goexits)
	n = copy(buf[n:], gostringnocopy(status))
	pid := getpid()

	bghelpers.Wait()

	xexit(2)
}

var atexits []func()

// xexit exits the process with return code n.
func xexit(n int) {
	for i := len(atexits) - 1; i >= 0; i-- {
		atexits[i]()
	}
	os.Exit(n)
}

// xatexit schedules the exit-handler f to be run when the program exits.
func xatexit(f func()) {
	atexits = append(atexits, f)
}

// xprintf prints a message to standard output.

// If all other goroutines exit, the program crashes.
func Goexit() {
	// Create a panic object for Goexit, so we can recognize when it might be
	// bypassed by a recover().
	var p _panic
	p.goexit = true

	p.start(getcallerpc(), unsafe.Pointer(getcallersp()))
	for {
		fn, ok := p.nextDefer()
		if !ok {
			break
		}
		fn()
	}

	goexit1()
}

type neverCallThisFunction struct{}

// goexit is the return stub at the top of every goroutine call stack.
// Each goroutine stack is constructed as if goexit called the
// goroutine's entry point function, so that when the entry point
// function returns, it will return to goexit, which will call goexit1
// to perform the actual exit.
//
// This function must never be called directly. Call goexit1 instead.

# Test that calling f.Fatal in a fuzz target causes a non-zero exit status.
! go test fatal_fuzz_test.go
! stdout ^ok
stdout FAIL

# Test that successful test exits cleanly.
go test success_fuzz_test.go
stdout ^ok
! stdout FAIL

# Test that successful fuzzing exits cleanly.
go test -fuzz=Fuzz -fuzztime=1x success_fuzz_test.go
stdout ok
! stdout FAIL

# Test that calling f.Fatal while fuzzing causes a non-zero exit status.

	// immediately) to unexpectedly block on reading from the pipe.
	var (
		nHangs       = runtime.GOMAXPROCS(0)
		nExits       = runtime.GOMAXPROCS(0)
		hangs, exits sync.WaitGroup
	)
	hangs.Add(nHangs)
	exits.Add(nExits)

	// ready is done when the goroutines have done as much work as possible to
	// prepare to create subprocesses. It isn't strictly necessary for the test,

	c.Fail()

	// Calling runtime.Goexit will exit the goroutine, which
	// will run the deferred functions in this goroutine,
	// which will eventually run the deferred lines in tRunner,
	// which will signal to the test loop that this test is done.
	//
	// A previous version of this code said:
	//
	//	c.duration = ...
	//	c.signal <- c.self
	//	runtime.Goexit()
	//

	want := "no goroutines (main called runtime.Goexit) - deadlock!"
	if !strings.Contains(output, want) {
		t.Fatalf("output:\n%s\n\nwant output containing: %s", output, want)
	}
}

func TestGoexitDefer(t *testing.T) {
	c := make(chan struct{})
	go func() {
		defer func() {
			r := recover()
			if r != nil {
				t.Errorf("non-nil recover during Goexit")
			}
			c <- struct{}{}
		}()

// called.
func fRunner(f *F, fn func(*F)) {
	// When this goroutine is done, either because runtime.Goexit was called, a
	// panic started, or fn returned normally, record the duration and send
	// t.signal, indicating the fuzz test is done.
	defer func() {
		// Detect whether the fuzz test panicked or called runtime.Goexit
		// without calling F.Fuzz, F.Fail, or F.Skip. If it did, panic (possibly