if w.waiting == w.running {
				// All done.
				w.wait.Broadcast()
				w.mu.Unlock()
				return
			}
			w.wait.Wait()
			w.waiting--
		}

		// Pick something to do at random,
		// to eliminate pathological contention
		// in case items added at about the same time
		// are most likely to contend.
		i := rand.Intn(len(w.todo))
		item := w.todo[i]
		w.todo[i] = w.todo[len(w.todo)-1]
		w.todo = w.todo[:len(w.todo)-1]

// returns a non-nil error or the first time Wait returns, whichever occurs
// first.
func WithContext(ctx context.Context) (*Group, context.Context) {
	ctx, cancel := withCancelCause(ctx)
	return &Group{cancel: cancel}, ctx
}

// Wait blocks until all function calls from the Go method have returned, then
// returns the first non-nil error (if any) from them.
func (g *Group) Wait() error {
	g.wg.Wait()
	if g.cancel != nil {
		g.cancel(g.err)

		},
		func(s *script.State, args ...string) (script.WaitFunc, error) {
			b := work.NewBuilder(s.Getwd())
			wait, err := cmdExec.Run(s, append(b.GccCmd(".", ""), args...)...)
			if err != nil {
				return wait, err
			}
			waitAndClean := func(s *script.State) (stdout, stderr string, err error) {
				stdout, stderr, err = wait(s)
				if closeErr := b.Close(); err == nil {
					err = closeErr
				}
				return stdout, stderr, err
			}

	wg.Add(2)
	go cpu10(&wg)
	go cpu20(&wg)
	wg.Wait()

	// checkHeapMetrics relies on this.
	allocHog(25 * time.Millisecond)

	// checkProcStartStop relies on this.
	var wg2 sync.WaitGroup
	for i := 0; i < runtime.GOMAXPROCS(0); i++ {
		wg2.Add(1)
		go func() {
			defer wg2.Done()
			cpuHog(50 * time.Millisecond)
		}()
	}
	wg2.Wait()

	// checkSyscalls relies on this.
	done := make(chan error)

	// will clobber the test pattern created by the caller
	ADD	$(1024*8), X2

	// Ask signaller to setgid
	MOV	$1, X5
	FENCE
	MOVW	X5, ·Baton(SB)
	FENCE

	// Wait for setgid completion
loop:
	FENCE
	MOVW	·Baton(SB), X5
	OR	X6, X6, X6	// hint that we're in a spin loop
	BNE	ZERO, X5, loop
	FENCE

	// Restore stack
	ADD	$(-1024*8), X2

	// will clobber the test pattern created by the caller
	ADDV	$(1024*8), R29

	// Ask signaller to setgid
	MOVW	$1, R1
	SYNC
	MOVW	R1, ·Baton(SB)
	SYNC

	// Wait for setgid completion
loop:
	SYNC
	MOVW	·Baton(SB), R1
	OR	R2, R2, R2	// hint that we're in a spin loop
	BNE	R1, loop
	SYNC

	// Restore stack
	ADDV	$(-1024*8), R29

# options it may have been built with, such as -trimpath or not.
# Instead, we build a fresh copy of the binary with known settings.
go build -o $WORK/new/bin/go$GOEXE cmd/go &
go build -trimpath -o $WORK/bin/check$GOEXE check.go &
wait

env TESTGOROOT=$GOROOT
env GOROOT=

# Relocated Executable
exec $WORK/bin/check$GOEXE $WORK/new/bin/go$GOEXE $TESTGOROOT

# Relocated Tree:

# Instead, we build a fresh copy of the binary with known settings.
go build -trimpath -o $WORK/new/bin/go$GOEXE cmd/go &
go build -trimpath -o $WORK/bin/check$GOEXE check.go &
wait

env TESTGOROOT=$GOROOT
env GOROOT=

# Unset GOPATH and any variables that its default may be derived from,
# so that we can check for a spurious warning.
env GOPATH=
env HOME=''
env USERPROFILE=''

	}
	err = toolCmd.Start()
	if err == nil {
		c := make(chan os.Signal, 100)
		signal.Notify(c)
		go func() {
			for sig := range c {
				toolCmd.Process.Signal(sig)
			}
		}()
		err = toolCmd.Wait()
		signal.Stop(c)
		close(c)
	}
	if err != nil {
		// Only print about the exit status if the command
		// didn't even run (not an ExitError) or it didn't exit cleanly

	if err != nil {
		return "", err
	}
	return strings.TrimSpace(s), nil
}

// close releases any resources used by the llvmSymbolizer object.
func (a *llvmSymbolizerJob) close() {
	a.in.Close()
	a.cmd.Wait()
}

// newLLVMSymbolizer starts the given llvmSymbolizer command reporting
// information about the given executable file. If file is a shared
// library, base should be the address at which it was mapped in the