def METHOD_NAME(self, exitcode, stderr):
    message = _(f"""The program {self.program_filter} exited with code {exitcode}.
                Any error messages it produced are shown below:""")
    dialog = gtk.MessageDialog(parent=None,
                               message_type=gtk.MessageType.ERROR,
                               text=message)
    dialog.add_buttons(gtk.STOCK_CLOSE, gtk.ResponseType.CLOSE)
    dialog.format_secondary_text(stderr)
    dialog.run()
    dialog.destroy()