gracePeriod = gp
		}

		// When we run commands that execute subprocesses, we want to reserve two
		// grace periods to clean up. We will send the first termination signal when
		// the context expires, then wait one grace period for the process to
		// produce whatever useful output it can (such as a stack trace). After the
		// first grace period expires, we'll escalate to os.Kill, leaving the second

	}

	n.SetTypecheck(2)
	n = typecheck1(n, top)
	n.SetTypecheck(1)

	t := n.Type()
	if t != nil && !t.IsFuncArgStruct() && n.Op() != ir.OTYPE {
		switch t.Kind() {
		case types.TFUNC, // might have TANY; wait until it's called
			types.TANY, types.TFORW, types.TIDEAL, types.TNIL, types.TBLANK:
			break

		default:
			types.CheckSize(t)
		}
	}

	return n
}

		})
}

// Wait waits for the completion of background commands.
//
// When Wait returns, the stdout and stderr buffers contain the concatenation of
// the background commands' respective outputs in the order in which those
// commands were started.
func Wait() Cmd {
	return Command(
		CmdUsage{
			Summary: "wait for completion of background commands",
			Args:    "",

	}

	if *fast {
		var wg sync.WaitGroup
		wg.Add(len(files))
		for _, filename := range files {
			go func(filename string) {
				defer wg.Done()
				action(filename)
			}(filename)
		}
		wg.Wait()
	} else {
		for _, filename := range files {
			action(filename)
		}
	}

	for _, dir := range dirs {
		walkDirs(t, dir, action)
	}
}

		go func() {
			defer func() {
				wg.Done()
				<-cpulimit
			}()

			_, err := c.getDirPackage(dir)
			if err != nil {
				t.Errorf("error checking %s: %v", dir, err)
			}
		}()
	}

	wg.Wait()

	if testing.Verbose() {
		fmt.Println(len(dirFiles), "packages typechecked in", time.Since(start))
	}
}

// stdlibChecker implements concurrent type-checking of the packages defined by