Fork A Repo

https://help.github.com/articles/fork-a-repo

主要是保证fork的repo是干净的

cd Spoon-Knife# Changes the active directory in the prompt to the newly cloned "Spoon-Knife" directory
git remote add upstream https://github.com/octocat/Spoon-Knife.git# Assigns the original repo to a remote called "upstream"
git fetch upstream# Pulls in changes not present in your local repository, without modifying your files

当然要合并才有价值

git fetch upstream# Fetches any new changes from the original repo
git merge upstream/master# Merges any changes fetched into your working files

其他参考原文