code: func generateErrString(failedClosers []closer) (errString string) {
  	for i, fc := range failedClosers {
  		if i == 0 {
  			errString = fmt.Sprintf("%s/%s: %s", fc.PKGPath, fc.Name, fc.Err)
  			continue
  		}
  		errString = fmt.Sprintf("%s, %s/%s: %s", errString, fc.PKGPath, fc.Name, fc.Err)
  	}
  
  	return errString
  }
docs: // generateErrString generates a string containing a list of tuples of pkgname to error message