On Ubuntu, I did the following once for the system to get a Ruby build system:
sudo apt install ruby-full build-essential
# install "bundler" for local user
gem install bundler --user-installThen I did the following in my clone of the vadholmen repo to get all standard github plugins, such as Jekyll themes:
bundle config set --local path 'vendor/bundle'
bundle installNow after every change I can do the following (from .github/workflow/lint.yml):
bundle exec jekyll build
bundle exec htmlproofer ./_site --assume-extension --disable-external --ignore-urls "/connect\.facebook\.net/"