~$ time gem install jekyll
Fetching jekyll-4.2.1.gem
Successfully installed jekyll-4.2.1
Parsing documentation for jekyll-4.2.1
Before reporting this, could you check that the file you're documenting
has proper syntax:

  /usr/bin/ruby.exe -c lib/jekyll/commands/doctor.rb

RDoc is not a full Ruby parser and will fail when fed invalid ruby programs.

The internal error was:

        (NoMethodError) undefined method `[]' for nil:NilClass

ERROR:  While executing gem ... (NoMethodError)
    undefined method `[]' for nil:NilClass

real    0m7.718s
user    0m0.984s
sys     0m2.125s