knst:~/work/guides (master)$ docker run --rm --volume="$PWD:/srv/jekyll" jekyll/jekyll:3.8 jekyll build
ruby 2.6.3p62 (2019-04-16 revision 67580) [x86_64-linux-musl]
/usr/local/lib/ruby/gems/2.6.0/gems/bundler-2.0.2/lib/bundler/resolver.rb:287:in `block in verify_gemfile_dependencies_are_found!': Could not find gem 'coderay (~> 1.1.2)' in any of the gem sources listed in your Gemfile. (Bundler::GemNotFound)
from /usr/local/lib/ruby/gems/2.6.0/gems/bundler-2.0.2/lib/bundler/resolver.rb:255:in `each'
from /usr/local/lib/ruby/gems/2.6.0/gems/bundler-2.0.2/lib/bundler/resolver.rb:255:in `verify_gemfile_dependencies_are_found!'
from /usr/local/lib/ruby/gems/2.6.0/gems/bundler-2.0.2/lib/bundler/resolver.rb:49:in `start'
from /usr/local/lib/ruby/gems/2.6.0/gems/bundler-2.0.2/lib/bundler/resolver.rb:22:in `resolve'
from /usr/local/lib/ruby/gems/2.6.0/gems/bundler-2.0.2/lib/bundler/definition.rb:258:in `resolve'
from /usr/local/lib/ruby/gems/2.6.0/gems/bundler-2.0.2/lib/bundler/definition.rb:170:in `specs'
from /usr/local/lib/ruby/gems/2.6.0/gems/bundler-2.0.2/lib/bundler/definition.rb:237:in `specs_for'
from /usr/local/lib/ruby/gems/2.6.0/gems/bundler-2.0.2/lib/bundler/definition.rb:226:in `requested_specs'
from /usr/local/lib/ruby/gems/2.6.0/gems/bundler-2.0.2/lib/bundler/runtime.rb:108:in `block in definition_method'
from /usr/local/lib/ruby/gems/2.6.0/gems/bundler-2.0.2/lib/bundler/runtime.rb:20:in `setup'
from /usr/local/lib/ruby/gems/2.6.0/gems/bundler-2.0.2/lib/bundler.rb:107:in `setup'
from /usr/gem/gems/jekyll-3.8.6/lib/jekyll/plugin_manager.rb:50:in `require_from_bundler'
from /usr/gem/gems/jekyll-3.8.6/exe/jekyll:11:in `<top (required)>'
from /usr/gem/bin/jekyll:23:in `load'
from /usr/gem/bin/jekyll:23:in `<main>'