Using Windows Subsystem for Linux and Ruby with Jekyll

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The Goal / Problem

This blog has been around for a little bit now. I’m bound to have some dead links or images. I figured I’d check those out and clean up the place.

Luckily, this blog also runs on Jekyll and Ruby, and the ruby ecosystem has a great gem called html-proofer that will help us do this.

So I added the gem to my project, installed it, and ran html-proofer, only to see:

(LoadError)y23/lib/ruby/gems/2.3.0/gems/ffi-1.9.18-x64-mingw32/lib/ffi/library.rb:147:in `block in ffi_lib’: Could not open library ‘libcurl’: The specified module could not be found.

Could not open library ‘’: The specified module could not be found.

That’s…not great. I googled a bunch and it appears that some of the tools in that chain don’t play well with Windows, and I wasn’t able to find a solution quickly. So I was about to give up on the task for a bit rather than fighting the Ruby/Windows ecosystem.

…until I remembered that I could bring Linux right into my environment and get the job done.

The Solution: Enter Windows Subsystem for Linux (WSL)

If you haven’t heard of Windows System for Linux (WSL), it’s a fantastic project from Microsoft that allows you to run certain Linux distributions right from within Windows, allowing you to get the best of both worlds.

I figured it was worth giving it a shot. Boy, was I right.

Obtaining WSL

I opened the Microsoft Store App and searched for “Ubuntu”. I found the Ubuntu distribution from Canonical and clicked Install. When that was done, I clicked Launch.

I waited a few minutes for some setup to complete, followed the prompts to create a username and password, and then I had a shell ready to go.

…was it really that straight-forward? Indeed it was.

Installing Ruby

RVM seemed like the right way to go to install and manage versions of Ruby, so I decided to use that.

I followed the install instructions. All of the below steps were performed within the Ubuntu window.

  • Accept the public keys: gpg --keyserver hkp:// --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3 7D2BAF1CF37B13E2069D6956105BD0E739499BDB
  • Install some prerequisites for rvm: sudo apt-get install software-properties-common
  • Add the RVM source repo: sudo apt-add-repository -y ppa:rael-gc/rvm
  • Update apt-get: sudo apt-get update
  • Install RVM: sudo apt-get install rvm

After RVM installs, it prints out some additional instructions, so I also:

  • Add my user to the “rvm” group: sudo usermod -a -G rvm sean
  • Run the additional post-install script: source /etc/profile.d/
  • Logout of the vm: logout
  • Re-launch the app from within Windows and bring the shell back up.

I then used RVM to install Ruby: rvm install ruby

Cool! I’ve got Ruby.

Git Install and Clone

I’ve got to get to my blog’s repository in order to build it and run html-proofer. That means setting up git with the GitHub repo. I:

  • Install git: sudo apt-get install git
  • Set my username: git config --global "SeanKilleen"
  • Set my e-mail: git config --global "[email protected]"
  • Check out the blog repo: git clone

Building the Blog

I need to:

  • Go into the blog’s directory: cd
  • Install Bundler: gem install bundler
  • Install the gems for the blog: bundle install

Now, I can build the blog via bundle exec jekyll build

And it works! Not shabby.

Adding html-proofer (from Windows!)

OK, so I need to add the html-proofer gem by modifying the gemfile that’s sitting on my Ubuntu distro. But ugh, I don’t know the landscape as well as I know the windows landscape, and I’d rather just quickly use notepad.

…Thankfully, you can totally edit the Linux distro files from within Windows!


  • Opened Windows Explorer
  • Navigated to C:\Users\%USERNAME%\AppData\Local\Packages
  • Clicked into the Ubuntu distro folder: CanonicalGroupLimited.UbuntuonWindows_79rhkp1fndgsc
  • Navigated to \LocalState\rootfs\home\sean

Whoa, there’s my repo folder! I just need to click into the folder, and then I can open gemfile within notepad.

  • I add a line: gem 'html-proofer' and save.
  • I then switch back into my Ubuntu Window. I type cat gemfile and lo and behold, I see my changes reflected there. Nice!

It would be pretty great to commit those changes to GitHub right from my Ubuntu distro. Is that doable?

…Heck yeah, it’s doable.

Setting up my GitHub account for push within WSL

Pushing to GitHub requires a personal access token when you have two-factor authentication turned on (as you should!). So, I:

  • Open a web browser on Windows and head to
  • Create a personal access token and save it somewhere that you would save a password (because it essentially is one)
  • Switch back to my Ubuntu WSL window
  • Navigate to the repo folder if I’m not already in it
  • Add my uncommitted files: git add .
  • Check with git status
  • Commit the change: git commit -m "Adding html-proofer gem"
  • Attempt to push the change: git push
  • Enter username and personal access token in place of the password

Now I’ve committed the change to my repo, from Ubuntu.

The payoff: Running html-proofer without issue!

In my WSL window, I:

  • Navigate to the repo folder
  • Run bundle install to make sure I’ve got everything installed
  • Run bundle exec jekyll build to create the output, which lives in a _site folder.
  • Run bundle exec html-proofer ./_site to execute html-proofer.

Voila! I see the output.

Wow. That was cool.

The team behind WSL has put in a ton of work to make this experience seamless. A small bit of googling let me follow instructions to get up and running on Ubuntu without sacrificing the ease and muscle memory of the Windows environment as my main setup.

I hope this helps serve as an introduction to Windows Subsystem for Linux. But if you’ll excuse me for now, I have some links to go fix!


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