Doesn't appear to work with github pages project site

[Kimeiga]

My site is deployed to here
I have an about page, "about.md", within _pages. I have this ruby script within plugins.
I run jekyll serve from the root of the project and it works!
I deploy to github pages and it does not work.

Perhaps an issue with #{site.source}#{site.baseurl}/#{pages_dir} (line 5)
Jekyll 3.3 removed the need to use site.baseurl by introducing relative_path.
Perhaps that's what's needed.