Upgrading from 3.x to 4.x
A few things have changed in Jekyll 4.
Before we dive in, you need to have at least Ruby 2.4.0 installed.
Run the following in your terminal to check
ruby -v ruby 2.6.3p62 (2019-04-16 revision 67580)
If you’re using a supported Ruby version >= 2.4.0, go ahead and fetch the latest version of Jekyll:
gem update jekyll
post_url Tag and Baseurl
post_url tag now incorporates the
relative_url filter within itself
and therefore automatically prepends your site's
baseurl to the post's
Please ensure that you change all instances of the
post_url usage as following:
We’ve slightly altered the way Jekyll parses and renders your various templates to improve the overall build times. Jekyll now parses a template once, caches it internally and then renders the parsed template multiple times as required by your pages and documents.
The downside to this is that some of the community-authored plugins may not work as they previously used to.
Static files in unrendered collections
Collections other than
posts can contain static assets along with Markdown files.
But if the collection has not been configured with metadata
output: true, then
neither its documents nor its static assets will be output to the destination
For plugin authors
If your plugin depends on the following code:
site.liquid_renderer.file(path).parse(content), note that the return value (
template, an instance of
Liquid::Template), from that line will always be the same object for a given
templateinstance is then rendered as previously, with respect to the
payloadpassed to it. You’ll therefore have to ensure that
payloadis not memoized or cached in your plugin instance.
If its a requirement that
templateyou get from the above step be different at all times, you can invoke
- template = site.liquid_renderer.file(path).parse(content) + template = Liquid::Template.parse(content)
We’ve enhanced our default exclusion array. It now looks like the following:
# default excludes exclude: - .sass-cache/ - .jekyll-cache/ - gemfiles/ - Gemfile - Gemfile.lock - node_modules/ - vendor/bundle/ - vendor/cache/ - vendor/gems/ - vendor/ruby/
What’s new is that this array does not get overridden by the
in the user’s config file anymore. The user’s exclude entries simply get
added to the above default array (if the entry isn’t already excluded).
To forcibly “process” directories or files that have been excluded, list them
include array instead:
# overrides your excluded items configuration and the default include array ([".htaccess"]) include: - .htaccess - node_modules/uglifier/index.js
The above configuration directs Jekyll to handle only
node_modules/uglifier/index.js while ignoring every other file in the
node_modules directory since that directory is “excluded” by default.
Note that the default
include array still gets overridden by the
array in your config file. So, be sure to add
.htaccess to the list if you
need that file to be present in the generated site.
Jekyll has dropped support for
kramdown requires specific extensions to be additionally installed to use
certain features are desired outside of kramdown’s core functionality.
Out of all the extensions listed in the report linked above, gem
kramdown-parser-gfm is automatically installed along with Jekyll 4.0. The
remaining extensions will have to be manually installed by the user depending on
desired funtionality, by listing the extension’s gem-name in their
kramdown-converter-pdfwill be ignored by Jekyll Core. To have Jekyll convert Markdown to PDF you’ll have to depend on a plugin that subclasses
Jekyll::Converterwith the required methods.
module Jekyll External.require_with_graceful_fail "kramdown-converter-pdf" class Markdown2PDF < Converter safe true priority :low def matches(ext) # match only files that have an extension exactly ".markdown" ext =~ /^\.markdown$/ end def convert(content) Kramdown::Document.new(content).to_pdf end def output_ext ".pdf" end end end
Vendors that provide a versioned Jekyll Environment Image (e.g. Docker Image, GitHub Pages, etc) will have to manually whitelist kramdown’s extension gems in their distributions for Jekyll 4.0.
Deprecated Configuration Options
Jekyll 4.0 has dropped support for all legacy configuration options that were deprecated over multiple releases in the previous series.
To that end, we shall no longer output a deprecation warning when we encounter a legacy config key nor
shall we gracefully assign their values to the newer counterparts. Depending on the key, it shall either
be ignored or raise an
InvalidConfigurationError error if the key is still valid but the associated
value is not of the valid type.