Change Jekyll Theme without forking the theme repository

Context:

Originally, I have a jekyll with default theme. But, in this theme, I can not categorize the blog posts. So, I want to change the theme to support categories.

I found a template that looks good to me. Problem is most of the themes mentioned that we need to fork their repository and copy-paste all of the posts. However, I don’t want to fork the new theme repository. Instead, I want to reuse my original repository.

I found a SO. I followed the instruction to create a new branch:

git checkout --orphan newtheme
git rm -rf .
git clean -dfx

Then, set the upstream to the new repository to pull the code into the new branch in local.

git remote add upstream https://github.com/the-mvm/the-mvm.github.io.git
git fetch upstream
git pull upstream main

After pulling the code from theme template, I will copy the files in my posts and drafts folder from main branch.

git checkout main -- _posts
git checkout main -- _drafts
git checkout main -- CNAME

Problem:

When merging the main with newtheme: git merge -s ours main I met an error: fatal: refusing to merge unrelated histories.

Solution:

The reason is that I opened a completely new branch without any shared commits. I solved this issue by merging the main branch into newtheme and resolve all of the conflicts.

git checkout newtheme
git merge main

At last,

git checkout main
git merge newtheme

Reference

• Switch theme in an existing Jekyll installation
• The MVM GitHub repository

Bao-Jhih Shao

A software engineer writing something to keep the memory.