code: func emptyExitedGarbage(gracePeriod time.Duration) error {
  	if err := pkgPod.WalkPods(getDataDir(), pkgPod.IncludeExitedGarbageDir, func(p *pkgPod.Pod) {
  		gp := p.Path()
  		st := &syscall.Stat_t{}
  		if err := syscall.Lstat(gp, st); err != nil {
  			if err != syscall.ENOENT {
  				stderr.PrintE(fmt.Sprintf("unable to stat %q, ignoring", gp), err)
  			}
  			return
  		}
  
  		if expiration := time.Unix(st.Ctim.Unix()).Add(gracePeriod); time.Now().After(expiration) {
  			if err := p.ExclusiveLock(); err != nil {
  				return
  			}
  			stdout.Printf("Garbage collecting pod %q", p.UUID)
  
  			deletePod(p)
  		} else {
  			stderr.Printf("pod %q not removed: still within grace period (%s)", p.UUID, gracePeriod)
  		}
  	}); err != nil {
  		return err
  	}
  
  	return nil
  }
docs: // emptyExitedGarbage discards sufficiently aged pods from exitedGarbageDir()