code: func cmdOutputDirErr(dir, command string, args ...string) (string, error) {
  	// NOTE: We only show these non-state-modifying commands with -v -v.
  	// Otherwise things like 'git sync -v' show all our internal "find out about
  	// the git repo" commands, which is confusing if you are just trying to find
  	// out what git sync means.
  
  	cmd := exec.Command(command, args...)
  	if dir != "." {
  		cmd.Dir = dir
  	}
  	b, err := cmd.CombinedOutput()
  	return string(b), err
  }
docs: // cmdOutputDirErr runs the command line in dir, returning its output
  // and any error results.
  //
  // NOTE: cmdOutputDirErr must be used only to run commands that read state,
  // not for commands that make changes. Commands that make changes
  // should be run using runDirErr so that the -v and -n flags apply to them.