Run a local build with bundle exec jekyll serve
Merge changes to master branch and push to Github.
sudo apt install ruby-full
# if this does not work because rubygems cannot be reached, adjust IPv6
# setting for this IP in /etc/gai.conf (see https://stackoverflow.com/a/50349235/109942)
gem install bundler
bundle config set --local path .bundle/gems
bundle install
# see https://github.com/jekyll/jekyll/issues/8523
sudo gem install webrick
# For updates
bundle update
bundle lock