Another git process seems to be running in this repository
Try deleting index.lock file in your .git directory.
rm -f .git/index.lock
Such problems generally occur when you execute two git commands simultaneously; maybe one from the command prompt and one from an IDE.
Another git process seems to be running in this repository - Stack Overflow https://stackoverflow.com/questions/38004148/another-git-process-seems-to-be-running-in-this-repository
