I've got a bare bones Jekyll site (only the feed plugin) and am rolling my own plain css (assets/css/style.css).
I am running my site with bundle exec jekyll serve --watch and when it first builds, I correctly get my CSS file served.
However, after I change a file (html, md, or css) the site will rebuild but in the site directory there will be a asset/css/style.css that is populated with normalize.css rather than my own CSS.
Why is this happening? How do I prevent it? I need to constantly delete the generated site and rebuild to view changes in my site.
I believe that the normalize.css was coming from the GitHub pages plugin.
I solved this issue by adding:
theme: null
to my _config.yml file.
Now the CSS will properly rebuild every time.