new_contents: #!/usr/bin/env python
  # -*- coding: utf-8 -*-
  
  # This software is under a BSD license.  See LICENSE.txt for details.
  
  import sys
  
  _errors = []
  
  def DTErrorMessage(fcn, msg):
      err_msg = "%s: %s" % (fcn, msg)
      _errors.append(err_msg)
      sys.stderr.write(err_msg + "\n")
  
  def DTSaveError(datafile, name):
      if len(_errors):
          datafile[name] = _errors
  
subject: add error wrapper to echo to stderr