一、报错点

当修改部分系统api时，会提示更新

frameworks/base/api/system-current.txt

或者

frameworks/base/api/current.txt 

而安卓源码一般会有如下提示

******************************
You have tried to change the API from what has been previously approved.

To make these errors go away, you have two choices:
1) You can add "@hide" javadoc comments to the methods, etc. listed in the
errors above.

2) You can update current.txt by executing the following command:
make system-api-stubs-docs-update-current-api

To submit the revised current.txt to the main Android repository,
you will need approval.
******************************

一般来说我们使用选项2即可解决问题，更新api。

而这也是本文所遇到的问题，当使用

make system-api-stubs-docs-update-current-api

时报如下错误：

frameworks/native/vulkan/libvulkan/Android.bp:31:1: "libvulkan" depends on undefined module "libgpud_sys"

二、解决办法

中间使用了各种方法没有解决，这里直接给出解决方案，非常简单。

首先使用

make clean

清除掉out目录下编译产出的所有文件

然后整编即可，整编过程会更新current.txt 文件，但如果后续有改动，就会发生如上报错，重复上述步骤即可。

So easy !!!