def parse_metaconfig_line(line):
    """ Parses line and return key=value tuple """
    delimiter_pos = line.find('=')
    if delimiter_pos == -1:
        raise ValueError("'=' not found in metaconfig line " + line)
    var_name = line[:delimiter_pos].strip()
    if len(var_name) == 0:
        raise ValueError('variable name not found in metaconfig line ' + line)
    var_expr = line[delimiter_pos + 1:].strip()
    return var_name, var_expr
