code: def runtime_error(self, msg, method):
          
          if self.testing:
              self._py3_wrapper.report_exception(msg)
              raise KeyboardInterrupt
  
          if self.error_hide:
              self.hide_errors()
              return
  
          # only show first line of error
          msg = msg.splitlines()[0]
  
          errors = [self.module_nice_name, u"{}: {}".format(self.module_nice_name, msg)]
  
          # if we have shown this error then keep in the same state
          if self.error_messages != errors:
              self.error_messages = errors
              self.error_index = 0
          self.error_output(self.error_messages[self.error_index], method)
docs: Show the error in the bar