Another git process seems to be running in this repository

git add . 报错

Another git process seems to be running in this repository, e.g.
an editor opened by 'git commit'. Please make sure all processes
are terminated then try again. If it still fails, a git process
may have crashed in this repository earlier:
remove the file manually to continue.

原因：git被另外一个程序占用，重启机器也不能够解决。

原因在于Git在使用过程中遭遇了奔溃，部分被上锁资源没有被释放导致的。

解决方案：

　　进入项目文件夹下的 .git文件中【删除index.lock文件】，如若看不到该文件，需要显示隐藏文件夹。或者直接执行 【rm .git/index.lock】

注【显示文件夹

defaults write com.apple.finder AppleShowAllFiles -boolean true ; killall Finder

隐藏文件见

defaults write com.apple.finder AppleShowAllFiles -boolean false ; killall Finder】