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()) {

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

-- 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

-- 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

	size    int64
	cur     int64
	mu      sync.Mutex
	waiters list.List
}

// Acquire acquires the semaphore with a weight of n, blocking until resources
// are available or ctx is done. On success, returns nil. On failure, returns
// ctx.Err() and leaves the semaphore unchanged.
func (s *Weighted) Acquire(ctx context.Context, n int64) error {
	done := ctx.Done()

	s.mu.Lock()
	select {
	case <-done:

	Requires: []*analysis.Analyzer{inspect.Analyzer},
	Run:      run,
}

// assertableTo checks whether interface v can be asserted into t. It returns
// nil on success, or the first conflicting method on failure.
func assertableTo(free *typeparams.Free, v, t types.Type) *types.Func {
	if t == nil || v == nil {
		// not assertable to, but there is no missing method
		return nil
	}
	// ensure that v and t are interfaces

// is tricky because we'd have to run updateExprType on the argument first.
// (go.dev/issue/21982.)

// convertibleTo reports whether T(x) is valid. In the failure case, *cause
// may be set to the cause for the failure.
// The check parameter may be nil if convertibleTo is invoked through an
// exported API call, i.e., when all methods have been type-checked.

					leaf = line.Function.Name
				}
			}
			// runtime.sigprof synthesizes call stacks when "normal traceback is
			// impossible or has failed", using particular placeholder functions
			// to represent common failure cases. Look for those functions in
			// the leaf position as a sign that the call stack and its
			// symbolization are more complex than this test can handle.
			//

// recovered is the result of invoking recover after running the test, in case it panicked.
//
// If stdout doesn't match the expected output or if recovered is non-nil, it'll print the cause of failure to stdout.
// If the test is chatty/verbose, it'll print a success message to stdout.
// If recovered is non-nil, it'll panic with that value.
// If the test panicked with nil, or invoked runtime.Goexit, it'll be

//
// When a benchmark runs, it typically produces a single line of output
// giving timing results. That line is reported in an event with Action == "output"
// and no Test field. If a benchmark logs output or reports a failure
// (for example, by using b.Log or b.Error), that extra output is reported
// as a sequence of events with Test set to the benchmark name, terminated
// by a final event with Action == "bench" or "fail".