jekyll 3.8.5 | Error: undefined method `each' for nil:NilClass

[sparanoid]

I want to report a bug:

This plugins current conflicts with jekyll-polyglot

What is the current behavior?

Run:

$ ALGOLIA_API_KEY='my_api_key' bundle exec jekyll algolia --trace

Got the following error:

Configuration file: /Users/sparanoid/Git/openbayes-homepage/_config.yml
Processing site...                                                               
bundler: failed to load command: jekyll (/usr/local/lib/ruby/gems/2.6.0/bin/jekyll)
NoMethodError: undefined method `each' for nil:NilClass
  /usr/local/lib/ruby/gems/2.6.0/gems/jekyll-polyglot-1.3.1/lib/jekyll/polyglot/patches/jekyll/site.rb:127:in `document_url_regex'
  /usr/local/lib/ruby/gems/2.6.0/gems/jekyll-polyglot-1.3.1/lib/jekyll/polyglot/patches/jekyll/site.rb:94:in `coordinate_documents'
  /usr/local/lib/ruby/gems/2.6.0/gems/jekyll-polyglot-1.3.1/lib/jekyll/polyglot/hooks/coordinate.rb:20:in `block in hook_coordinate'
  /usr/local/lib/ruby/gems/2.6.0/gems/jekyll-polyglot-1.3.1/lib/jekyll/polyglot/hooks/coordinate.rb:19:in `each'
  /usr/local/lib/ruby/gems/2.6.0/gems/jekyll-polyglot-1.3.1/lib/jekyll/polyglot/hooks/coordinate.rb:19:in `hook_coordinate'
  /usr/local/lib/ruby/gems/2.6.0/gems/jekyll-polyglot-1.3.1/lib/jekyll/polyglot/hooks/coordinate.rb:4:in `block in <top (required)>'
  /usr/local/lib/ruby/gems/2.6.0/gems/jekyll-3.8.5/lib/jekyll/hooks.rb:103:in `block in trigger'
  /usr/local/lib/ruby/gems/2.6.0/gems/jekyll-3.8.5/lib/jekyll/hooks.rb:102:in `each'
  /usr/local/lib/ruby/gems/2.6.0/gems/jekyll-3.8.5/lib/jekyll/hooks.rb:102:in `trigger'
  /usr/local/lib/ruby/gems/2.6.0/gems/jekyll-3.8.5/lib/jekyll/site.rb:166:in `read'
  /usr/local/lib/ruby/gems/2.6.0/gems/jekyll-algolia-1.4.11/lib/jekyll/algolia/overwrites/jekyll-algolia-site.rb:23:in `process'
  /usr/local/lib/ruby/gems/2.6.0/gems/jekyll-algolia-1.4.11/lib/jekyll-algolia.rb:82:in `run'
  /usr/local/lib/ruby/gems/2.6.0/gems/jekyll-algolia-1.4.11/lib/jekyll/commands/algolia.rb:31:in `block (2 levels) in init_with_program'
  /usr/local/lib/ruby/gems/2.6.0/gems/mercenary-0.3.6/lib/mercenary/command.rb:220:in `block in execute'
  /usr/local/lib/ruby/gems/2.6.0/gems/mercenary-0.3.6/lib/mercenary/command.rb:220:in `each'
  /usr/local/lib/ruby/gems/2.6.0/gems/mercenary-0.3.6/lib/mercenary/command.rb:220:in `execute'
  /usr/local/lib/ruby/gems/2.6.0/gems/mercenary-0.3.6/lib/mercenary/program.rb:42:in `go'
  /usr/local/lib/ruby/gems/2.6.0/gems/mercenary-0.3.6/lib/mercenary.rb:19:in `program'
  /usr/local/lib/ruby/gems/2.6.0/gems/jekyll-3.8.5/exe/jekyll:15:in `<top (required)>'
  /usr/local/lib/ruby/gems/2.6.0/bin/jekyll:23:in `load'
  /usr/local/lib/ruby/gems/2.6.0/bin/jekyll:23:in `<top (required)>'

What is your expected behavior?

Should process successfully

Git repository to reproduce the issue:

https://github.com/signcl/openbayes.com

Ruby version used:

ruby 2.6.1p33 (2019-01-30 revision 66950) [x86_64-darwin18]

Jekyll version used:

jekyll 3.8.5