$ git add .
fatal: Unable to create 'D:/Git/ocr/.git/index.lock': File exists.
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.
解决办法:
进入对应项目的.git目录将index.lock文件删除 再重新添加