def set_raise_internal_errors(flag):
    """ If raise_internal_errors is set to True, then the errors in
        node execution are directly raised.

        If False, we will produce a wrapped messsage,
        which contains the line number where the
        node is declared. It is easier for debugging and in Python 3+
        the underlying error message is also printed.
    """
    global _raise_internal_errors
    _raise_internal_errors = flag
