def METHOD_NAME(rtconfig):
    exec_path = rtconfig.EXEC_PATH
    prefix = rtconfig.PREFIX
    if prefix.endswith('-'):
        prefix = prefix[:-1]
    if exec_path == '/usr/bin':
        root_path = os.path.join('/usr/lib', prefix)
    else:
        root_path = os.path.join(exec_path, '..', prefix)
    return root_path