if n != len(buf) || err != nil || string(buf) != "O:hi\n" {
		t.Fatalf("ReadFull = %d, %v, %q", n, err, buf[:n])
	}
	go cancel()

	if err := c.Wait(); err == nil {
		t.Fatal("expected Wait failure")
	}
}

func TestContextCancel(t *testing.T) {
	if runtime.GOOS == "netbsd" && runtime.GOARCH == "arm64" {
		maySkipHelperCommand("cat")
		testenv.SkipFlaky(t, 42061)
	}

	// and reinvoking the current binary.
	// The special cases =loop and =mismatch skip the
	// setting of TESTGO_VERSION so that it looks like we
	// accidentally invoked the wrong toolchain,
	// to test detection of that failure mode.
	switch TestVersionSwitch {
	case "switch":
		os.Setenv("TESTGO_VERSION", gotoolchain)
		fallthrough
	case "loop", "mismatch":
		exe, err := os.Executable()
		if err != nil {

			}
			return nil
		}); err != nil {
			// Internal errors are marked with f.Fail; user code may call this too, before F.Fuzz.
			// The worker will exit with fuzzWorkerExitCode, indicating this is a failure
			// (and 'go test' should exit non-zero) but a failing input should not be recorded.
			f.Errorf("communicating with fuzzing coordinator: %v", err)
		}

	default:

// If the file does not exist, WriteFile creates it with permissions perm (before umask);
// otherwise WriteFile truncates it before writing, without changing permissions.
// Since WriteFile requires multiple system calls to complete, a failure mid-operation
// can leave the file in a partially written state.
func WriteFile(name string, data []byte, perm FileMode) error {
	f, err := OpenFile(name, O_WRONLY|O_CREATE|O_TRUNC, perm)
	if err != nil {
		return err

				break
			}
		}
	}
}

// Issue 8410
func TestMapSparseIterOrder(t *testing.T) {
	// Run several rounds to increase the probability
	// of failure. One is not enough.
NextRound:
	for round := 0; round < 10; round++ {
		m := make(map[int]bool)
		// Add 1000 items, remove 980.
		for i := 0; i < 1000; i++ {
			m[i] = true
		}

	// Using After(10ms) but waiting for 500ms to read the channel
	// should produce a time from start+10ms, not start+500ms.
	// Make sure it does.
	// To avoid flakes due to very long scheduling delays,
	// require 10 failures in a row before deciding something is wrong.
	for range 10 {
		start := Now()
		c := After(10 * Millisecond)
		Sleep(500 * Millisecond)
		dt := (<-c).Sub(start)
		if dt < 400*Millisecond {
			return
		}

	}
}

func SkipFlakyNet(t testing.TB) {
	t.Helper()
	if v, _ := strconv.ParseBool(os.Getenv("GO_BUILDER_FLAKY_NET")); v {
		t.Skip("skipping test on builder known to have frequent network failures")
	}
}

// CPUIsSlow reports whether the CPU running the test is suspected to be slow.
func CPUIsSlow() bool {
	switch runtime.GOARCH {
	case "arm", "mips", "mipsle", "mips64", "mips64le", "wasm":

		for x[i] = 1; x[i] <= byte(max); x[i]++ {
			testRec(t, x, i+1, max, numFail, build)
		}
		return
	}

	if !testSA(t, x, build) {
		*numFail++
		if *numFail >= 10 {
			t.Errorf("stopping after %d failures", *numFail)
			t.FailNow()
		}
	}
}

// testSA tests the suffix array build function on the input x.
// It constructs the suffix array and then checks that it is correct.

				if i := strings.LastIndex(name, "/"); i >= 0 {
					name = name[i+1:]
				}
				imp = NewPackage(path, name)
			}
			// continue to use the package as best as we can
			imp.fake = true // avoid follow-up lookup failures
		}
	}

	// package should be complete or marked fake, but be cautious
	if imp.complete || imp.fake {
		check.impMap[key] = imp
		// Once we've formatted an error message, keep the pkgPathMap

				if i := strings.LastIndex(name, "/"); i >= 0 {
					name = name[i+1:]
				}
				imp = NewPackage(path, name)
			}
			// continue to use the package as best as we can
			imp.fake = true // avoid follow-up lookup failures
		}
	}

	// package should be complete or marked fake, but be cautious
	if imp.complete || imp.fake {
		check.impMap[key] = imp
		// Once we've formatted an error message, keep the pkgPathMap