docs: def on_error(e):  # pragma: no cover
      """Error handler
  
      RuntimeError or ValueError exceptions raised by commands will be handled
      by this function.
      """
      exname = {'RuntimeError': 'Runtime error', 'Value Error': 'Value error'}
      sys.stderr.write('{}: {}\n'.format(exname[e.__class__.__name__], str(e)))
      sys.stderr.write('See file slam_error.log for additional details.\n')
      sys.exit(1)