Git: Collaboration

FAIR & Reproducible Teaching with Quarto & Git
Course at University of Hamburg
Slides | Source
License: CC BY 4.0

Dr. Lennart Wittkuhn
lennart.wittkuhn@tutanota.com

14:00

Schedule

Day 1

Day Date Time Title
1 2026-03-20 09:30 - 10:00 Welcome & Introduction
1 2026-03-20 10:00 - 10:30 Quarto: Introduction
1 2026-03-20 10:30 - 10:45 Quarto: Presentations
1 2026-03-20 10:45 - 11:00 Git: Setup & Configuration
1 2026-03-20 11:00 - 11:15 Command Line
1 2026-03-20 11:15 - 12:00 Git: Basics
1 2026-03-20 12:00 - 13:00 Lunch Break
1 2026-03-20 13:00 - 14:00 Git: Remotes
1 2026-03-20 14:00 - 15:00 Git: Collaboration
1 2026-03-20 15:00 - 15:30 Quarto: Publication to GitHub Pages
1 2026-03-20 15:30 - 16:00 Git: Tags & Releases

1 Last session

Last session: Learning objectives

After the last session, you should now be able to answer the following questions / do the following:

💡 You can create a remote repository.
💡 You can connect your local Git repository to a remote repository service like GitHub or GitLab.
💡 You can pull and push changes to and from a remote repository.
💡 You can clone a repository from a remote repository.

2 This session: Git: Collaboration

Objectives

💡 You know the purpose and components of a Pull Request.
💡 You know how to collaborate using the popular workflow strategy GitHub flow.
💡 You know the purpose and components of a README file.
💡 You can fork a repository.
💡 You can create a Pull Request from a forked repository.
💡 You can protect your main branch.

Reading

GitHub - Advanced

Tasks

In this session, you will work on the following tasks:

  1. Reading: Read the chapter(s) GitHub - Advanced in the Version Control Book.
  2. Implementation: Try out the commands in the chapter.
  3. Exercises: Work on the exercises.

As always:

  1. Try out the commands of this session and play around with them.
  2. Check whether you have achieved the learning objectives.
  3. Ask questions!

GitHub Flow

Image from Sebass van Boxel

Exercises

“Public” collaboration with pull requests (using a fork and GitHub Flow)

  1. Find out what forking is.
  2. Fork the project repository of the course instructor or another course participant (ideally, someone who is not your collaborator from the previous exercise).
  3. Create an Issue in your new collaborator’s repository, indicating an entry that you think is still missing in their repository.
  4. Repeat the steps from the exercise on collaboration with remote repositories using the forked repository:
    1. Clone the forked repository to a sensible location on your computer.
    2. Create a new branch and make one or multiple commits “fixing” the Issue that you opened. If available, follow the contributing guide of your collaborator’s repository.
    3. Push your changes to the remote repository.
    4. Create a pull/merge request with your changes (hint: from the forked to the original repository) and refer to the Issue in your pull/merge request.

Reviewing pull requests

  1. View any pull requests that are created in your recipes repository.
  2. Review the changes made by the contributor in the pull request.
  3. If needed, discuss additional changes with the contributor in the pull request.
  4. Close the pull request by merging the proposed changes.

3 Solutions

Solutions: “Public” collaboration with pull requests

Code
#!/bin/bash

1git clone https://github.com/your-username/forked-repo-name.git /path/to/your/forked/directory
cd /path/to/your/forked/directory
2git checkout -b issue-fix-branch
echo "New entry" >> project.txt
git add project.txt
git commit -m "Add new entry to fix #1"
3git push origin issue-fix-branch
4# Create a pull request on GitHub
1
Forking is a process where you create a copy of someone else’s repository under your own account. It allows you to freely experiment with changes without affecting the original project.
2
To fork the project repository of another course participant: (1) Go to the GitHub repository you want to fork. (2) Click the Fork button at the top-right corner of the repository page. (3) Select your GitHub account to fork the repository.
3
Create an Issue, suggesting a missing entry: (1) Go to the Issues tab of your partner’s repository on GitHub. (2) Click New issue. Provide a title and description for the Issue, suggesting a missing entry. (3) Click Submit new issue.
4
Clone the forked repository, create a branch, commit changes, push, and open a pull request: