Works fine locally, but not on GH Pages

[sixtyfive]

Install missing gems with `bundle install`
Warning: The github-pages gem can't satisfy your Gemfile's dependencies. If you want to use a different Jekyll version or need additional dependencies, consider building Jekyll site with GitHub Actions: https://jekyllrb.com/docs/continuous-integration/github-actions/
To use retry middleware with Faraday v2.0+, install `faraday-retry` gem
  Conversion error: Jekyll::Converters::Scss encountered an error while converting 'theme/css/site.scss':
                    File to import not found or unreadable: vendor/rfs. Load paths: /github/workspace/theme/_sass /usr/local/bundle/gems/jekyll-theme-primer-0.6.0/_sass /usr/local/bundle/gems/jekyll-theme-primer-0.6.0/_sass /usr/local/bundle/gems/jekyll-theme-primer-0.6.0/_sass on line 6
/usr/local/bundle/gems/jekyll-sass-converter-1.5.2/lib/jekyll/converters/scss.rb:123:in `rescue in convert': File to import not found or unreadable: vendor/rfs. (Jekyll::Converters::Scss::SyntaxError)

Any idea how to fix the above? Gemfile is unchanged from yours:

# frozen_string_literal: true

source "https://rubygems.org"

gem "webrick"
gem "rouge"
gem "kramdown-parser-gfm"
gem "jekyll"

I think the SCSS error is unrelated to the Gem warning.

Simply out-commenting vendor/rfs in theme/_sass/bootstrap/_mixins.scss of course doesn't work because it breaks the rest of bootstrap and doesn't solve the root cause anyways.

I don't understand why the Pages build process doesn't find the file in the first places, since it is sitting right there, in theme/_sass/bootstrap/vendor/. Apparently, for your own site, the build worked fine 5 months ago, so I must be doing something wrong? - Or they changed the build process...

[sixtyfive]

Okay, fixed my own problem.

Your .gitignore has vendor in it when it should be vendor/bundle.

I'll leave the Issue open for you to notice.