今天帮同事上传一个代码（预生产环境），当我执行到git add 文件 的时候，出现了如下错误：
If no other git process is currently running, this probably means a
git process crashed in this repository earlier. Make sure no other git
process is running and remove the file manually to continue.
网上查了好多文章，总结一下，方便以后查看，以下是解决方案：
rm -f ./.git/index.lockbi
编译ICS时出现以下错误：
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