fatal: Unable to create 'E:/workspace/source/.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. 위와 같이 git checkout 시에 에러가 발생하면 다른 프로세스에서 git ..