Installing ruby/Jekyll on Debian derivates can cause some trouble. In my experience Ruby and Ruby gems are a well integrated language/framework for MacOS but they do not become comfortable with Debian environments very easy.

So here are two workarounds: (1) Use a virtual machine like VirtualBox/Vagrant. Unfortunately Jekyll's directory watcher seems to have issues with some virtual file systems (file changes are not seen). (2) Install ruby, ruby gems, ruby-dev and the Jekyll dependencies manually. Maybe you will have to tinker around to find compatible jekyll-ruby-bootstrap versions for your system (change the version numbers in the Gemfile then run

$ bundle update

).

   # Generate docs with jekyll


This required nodejs/npm installed. If you have troubles installing npm
on Debian derivates, follow these instructions:
https://tecadmin.net/install-latest-nodejs-npm-on-debian/

You would have to run these commands
$ sudo apt-get install curl software-properties-common
$ curl -sL https://deb.nodesource.com/setup_11.x | sudo bash -


# Jekyll requires Ruby to installed (gem command)

Install ruby and ruby-dev for your matching version
$ sudo apt-get install ruby ruby-all-dev
$ sudo apt-get install ruby`ruby -e 'puts RUBY_VERSION[/\d+\.\d+/]'`-dev
$ sudo apt-get install ruby-full build-essential zlib1g-dev

# Run the bundler
$ sudo gem install bundler
$ bundle update
$ sudo gem install jekyll redcarpet
$ bundle exec jekyll serve

If there are still problems try
$ sudo gem update
and repeat the last 4 steps.



# Compile
Now run
$ bundle exec jekyll serve
for continuous local HTML generation

or

$ bundle exec jekyll build
for building the docs for production.

Have fun with Jekyll!
(~￣▽￣)~