I’ll introduce the procedure for syncing a forked repository on GitHub to follow the original repository.

Prerequisites

We assume you’ve already forked some repository on GitHub.

Git clone the forked repository

First, git clone the forked repository.

git clone git@github.com:your_account/sample_repository.git

Set the original forked repository as a remote repository named upstream

Set the original repository you forked from as a remote repository with the name “upstream”.

git remote add upstream git://github.com/original_account/sample_repository.git

From now on, you can handle the original forked repository with the name “upstream”.

You only need to set this up once initially; no reconfiguration is needed.

Confirm the upstream repository with git branch -a

$ git branch -a
* master
  remotes/origin/HEAD -> origin/master
  remotes/origin/master
  remotes/upstream/master

Git fetch and merge to follow changes in the original repository

First, git fetch upstream

$ git fetch upstream
remote: Counting objects: 1, done.
remote: Total 1 (delta 0), reused 1 (delta 0)
Unpacking objects: 100% (1/1), done.
From git://github.com/original_account/sample_repository
 * [new branch]      develop    -> upstream/develop
 * [new branch]      master     -> upstream/master

Then git merge

Merge the differences obtained with git fetch into the current branch.

$ git merge upstream/master
Updating 1e579f8..21e70ae
Fast-forward

For those unfamiliar with OSS development, working with forked repositories on GitHub and syncing with the original branch is probably uncommon, so I hope this article helps even a little.

Reference Information

• GitHubでFork/cloneしたリポジトリを本家リポジトリに追従する - Qiita

That’s all from the Gemba.