How To Fork A Subdirectory Of Repo As A Different Repo On GitHub

The Story

Ever wanted to fork a subdirectory and not the whole Git/GitHub repository. Well I have, I recently had to fork a subdirectory of one of the repositories I wanted to work on without the need to fork the whole repository. In this post, I will show you how it's done.

Note: I do not think you can fork subdirectories through GitHub's web interface

The How

Clone the repo

git clone https://github.com/<someones-username>/<some-repo-you-want-to-fork>
cd some-repo-you-want-to-fork

Create a branch using the git subtree command for the folder only

git subtree split --prefix=./src -b dir-you-want-to-fork
git checkout dir-you-want-to-fork

Create a new GitHub repo

Head over to GitHub and create a new repository you wish to fork the directory to.

Add the newly created repo as a remote

cd some-repo-you-want-to-fork
git remote set-url origin https://github.com/<username>/<new_repo>.git

Push the subtree to the new repository

git fetch origin -pa
git push -u origin dir-you-want-to-fork

Fetch all remote branches in the new repository

git clone https://github.com/<username>/<new_repo>.git
cd new_repo
git checkout --detach
git fetch origin '+refs/heads/*:refs/heads/*'
git checkout dir-you-want-to-fork

You now have a "fork" of the src subdirectory.

Merge to main/dev branch (troubleshooting)

If you ever run git merge master and get the error fatal: refusing to merge unrelated histories; run

git checkout dir-you-want-to-fork
git merge --allow-unrelated-histories master
# Fix conflicts and
git commit -a
git push origin dir-you-want-to-fork

Reference

• Splitting a subfolder out into a new repository
• StackOverflow