版权声明：随意转载，需注明出处。by think_ycx https://blog.csdn.net/think_ycx/article/details/84887557
使用git add时遇到错误：
fatal: Unable to create '/Volumes/APFS-case-sensitive/Tech/Pwn/thinkycx@pwn/.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：
rm .git/index.lock