1.今天 当我  执行  git add  somefile 的时候，出现 如下 错误：

If no other git process is currently running, this probably means agit process crashed in this repository earlier. Make sure no other gitprocess is running and remove the file manually to continue.

解决方法：

rm -f ./.git/index.lock

2. 编译ICS时 出现 如下错误：

build/core/java.mk:20: *** dalvik/dexgen: Invalid LOCAL_SDK_VERSION '4' Choices are: current .  Stop.

解决方法：

rm -rf prebuilt ; repo sync prebuilt