func (e *Expectation) Check(err error) error {
	if !e.failure && err != nil {
		return fmt.Errorf("unexpected error while reading the trace: %v", err)
	}
	if e.failure && err == nil {
		return fmt.Errorf("expected error while reading the trace: want something matching %q, got none", e.errorMatcher)
	}
	if e.failure && err != nil && !e.errorMatcher.MatchString(err.Error()) {

		if r == nil {
			panic("no fault or bounds check failure happened")
		}
		s := fmt.Sprintf("%s", r)
		if s != "runtime error: index out of range [1] with length 1" {
			panic("bad panic: " + s)
		}
	}()
	return uint16(x[i]) | uint16(x[i+1])<<8
}

func test32(x []byte) uint32 {
	defer func() {
		r := recover()
		if r == nil {
			panic("no fault or bounds check failure happened")
		}
		s := fmt.Sprintf("%s", r)

small:
	TESTQ	BX, BX
	JEQ	failure

	// Check if we'll load across a page boundary.
	LEAQ	16(SI), AX
	TESTW	$0xff0, AX
	JEQ	endofpage

	MOVOU	(SI), X1 // Load data
	PCMPEQB	X0, X1	// Compare target byte with each byte in data.
	PMOVMSKB X1, DX	// Move result bits to integer register.
	BSFL	DX, DX	// Find first set bit.
	JZ	failure	// No set bit, failure.
	CMPL	DX, BX

	var (
		respCh           = make(chan *Response, 1)
		errCh            = make(chan error, 1)
		success, failure js.Func
	)
	success = js.FuncOf(func(this js.Value, args []js.Value) any {
		success.Release()
		failure.Release()

		result := args[0]
		header := Header{}
		// https://developer.mozilla.org/en-US/docs/Web/API/Headers/entries

	alertDecryptionFailed:             "decryption failed",
	alertRecordOverflow:               "record overflow",
	alertDecompressionFailure:         "decompression failure",
	alertHandshakeFailure:             "handshake failure",
	alertBadCertificate:               "bad certificate",
	alertUnsupportedCertificate:       "unsupported certificate",
	alertCertificateRevoked:           "revoked certificate",

	if err != nil {
		t.Fatalf("build failure: %s\n%s\n", err, string(out))
	}

	// Check that we did split text sections.
	out, err = testenv.Command(t, testenv.GoToolPath(t), "tool", "nm", exe).CombinedOutput()
	if err != nil {
		t.Fatalf("nm failure: %s\n%s\n", err, string(out))
	}
	if !bytes.Contains(out, []byte("runtime.text.1")) {

-- expect --
FAILURE ".*expected a proc but didn't have one.*"
-- trace --
Trace Go1.22
EventBatch gen=1 m=0 time=0 size=34
GoCreateSyscall dt=1 new_g=4
ProcStatus dt=1 p=0 pstatus=2
ProcStart dt=1 p=0 p_seq=1
GoSyscallEndBlocked dt=1
GoStart dt=1 g=4 g_seq=1
GoSyscallBegin dt=1 p_seq=2 stack=0
GoDestroySyscall dt=1
GoCreateSyscall dt=1 new_g=4
GoSyscallEnd dt=1
GoSyscallBegin dt=1 p_seq=3 stack=0
GoDestroySyscall dt=1

	void *p;

	_cgo_tsan_acquire();
	p = mmap(addr, length, prot, flags, fd, offset);
	_cgo_tsan_release();
	if (p == MAP_FAILED) {
		/* This is what the Go code expects on failure.  */
		return (uintptr_t)errno;
	}
	return (uintptr_t)p;
}

void
x_cgo_munmap(void *addr, uintptr_t length) {
	int r;

	_cgo_tsan_acquire();
	r = munmap(addr, length);
	_cgo_tsan_release();

-- expect --
FAILURE "expected a proc but didn't have one"
-- trace --
Trace Go1.22
EventBatch gen=1 m=0 time=0 size=5
Frequency freq=15625000
EventBatch gen=1 m=0 time=0 size=5
GoCreate dt=0 new_g=1 new_stack=0 stack=0

				realTest.Error("sequential test was not run")
			}
		},
	}, {
		desc:   "failure in parallel test propagates upwards",
		ok:     false,
		maxPar: 1,
		output: `
--- FAIL: failure in parallel test propagates upwards (N.NNs)
    --- FAIL: failure in parallel test propagates upwards/#00 (N.NNs)
        --- FAIL: failure in parallel test propagates upwards/#00/par (N.NNs)
        `,
		f: func(t *T) {