springboot源码gradle 编译报错

springboot源码gradle 编译报错，如下：

> Task :buildSrc:compileJava FAILED

Execution failed for task ':buildSrc:compileJava'.

> 无效的源发行版: 17

* Try:

> Run with --stacktrace option to get the stack trace.

> Run with --info or --debug option to get more log output.

我看到build.gradle 中有2行

sourceCompatibility = targetCompatibility =

我把他改成

sourceCompatibility = 8
targetCompatibility = 

还是不行，麻烦老师给看看