Q: How to view your bundler version?

cat Gemfile.lock | grep -A 1 "BUNDLED WITH"

Q: How to override settings

Change the settings in assets/css/main.scss.

Q: How to change your home page?

Change settings in index.html.

Q: How to uninstall all gems?

gem uninstall -aIx

Q: How to resolve incompatible ruby gems

ruby_dep-1.5.0 requires ruby version >= 2.2.5, ~> 2.2, which is incompatible
with the current version, ruby 3.0.2p107

bundle update

Q: How to solve cannot load such file (LoadError)

λ bundle exec jekyll serve
C:/Ruby30-x64/lib/ruby/gems/3.0.0/gems/jekyll-3.9.0/lib/jekyll/commands/serve/servlet.rb:3:in `require': cannot load such file -- webrick (LoadError)

bundle add webrick

Q: How to resolve cannot load such file rubyeventmachine (LoadError)

Unable to load the EventMachine C extension; To use the pure-ruby reactor, require 'em/pure_ruby'
C:/Ruby30-x64/lib/ruby/gems/3.0.0/gems/eventmachine-1.2.7-x64-mingw32/lib/rubyeventmachine.rb:2:in `require': cannot load such file -- 3.0/rubyeventmachine (LoadError)
gem uninstall eventmachine 
gem 'eventmachine', '1.2.7', git: 'https://github.com/eventmachine/eventmachine.git', tag: 'v1.2.7'
bundle install
bundle exec jekyll

See: https://stackoverflow.com/a/65547010