Could not determine the dependencies of task ‘:app:compileDebugJavaWithJavac’.
> Failed to find Build Tools revision 29.0.2

This question:

1. Is this version available in the build tools in the SDK? If not, install

2. Your sdk directory has been modified, if you modify it, you need to re-define the sdk path for flutter

flutter config --android-sdk E:/Android_SDK

The E:/Android_SDK at the back is my modified sdk path. After running, restart the compiler and you can compile normally in flutter run