Gems on GH Pages

Environment for standard GH Pages set up (without GH Actions)

See the Dependency versions page for what gems GH Pages uses for builds.

You can enable these using plugins field of your config.

But GH Pages will ignore your Gemfile so you can’t add other gems or to change a version.

Jekyll versions

  • 3.8.5
    • Up to the end of 2020, this was used on GH Pages. There is a ticket open on the Jekyll repo around upgrade to Jekyll 4 but that is a long way off.
  • 3.9.0
    • At the end of 2020, GH Pages upgrade Jekyll to 3.9 to fix a security issue. That can also be fixed an automated security PR which does the following in your Gemfile.lock: ```diff
      • kramdown (2.2.1)
      • kramdown (2.3.0) ```
    • It also means that the kramdown-parser-gfm gem has to be installed explicitly for local builds. So add it to your Gemfile file. It will install kramdown. See on Kramdown V2 in in Jekyll 3 to 4 docs.
    • Sample 
        gem 'jekyll', '~> 3.9'
  gem 'kramdown-parser-gfm', '~> 1.1.0'
  • 4.X
    • Jekyll 4 is available through GH Actions and Netlify, if you configure your build and choose your Jekyll version. See Jekyll 3 to 4 in the docs.
    • Note that kramdown-parser-gfm is already included in the lockfile for a build of Jekyll 4.1 at least so you don’t have to add this to your Gemfile. The Kramdown version is also already higher, so the vulnerability from above is not relevant.
    • Sample: 
        gem 'jekyll', '~> 4.1'

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