title: Rails 6.1, Ruby 3.0.0: tests error as they cannot load rexml
body: <p>I've created a new Rails 6.1 application from scratch with Ruby 3.0.0.</p>
  <p>I've run <code>db:create</code> and generated a single model with some string columns, followed by <code>rails db:migrate</code>.</p>
  <p>I ran <code>rails test</code> but got this require rexml error:</p>
  <pre><code>/Users/froop/.rvm/gems/ruby-3.0.0/gems/bootsnap-1.5.1/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:34:in `require': cannot load such file -- rexml/document (LoadError)
    from /Users/froop/.rvm/rubies/ruby-3.0.0/lib/ruby/gems/3.0.0/gems/activesupport-6.1.0/lib/active_support/dependencies.rb:332:in `block in require'
    from /Users/froop/.rvm/rubies/ruby-3.0.0/lib/ruby/gems/3.0.0/gems/activesupport-6.1.0/lib/active_support/dependencies.rb:299:in `load_dependency'
    from /Users/froop/.rvm/rubies/ruby-3.0.0/lib/ruby/gems/3.0.0/gems/activesupport-6.1.0/lib/active_support/dependencies.rb:332:in `require'
    from /Users/froop/.rvm/gems/ruby-3.0.0/gems/selenium-webdriver-3.142.7/lib/selenium/webdriver/firefox.rb:22:in `&lt;main&gt;'
    from /Users/froop/.rvm/gems/ruby-3.0.0/gems/bootsnap-1.5.1/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:23:in `require'
    from /Users/froop/.rvm/gems/ruby-3.0.0/gems/bootsnap-1.5.1/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:23:in `block in require_with_bootsnap_lfi'
    from /Users/froop/.rvm/gems/ruby-3.0.0/gems/bootsnap-1.5.1/lib/bootsnap/load_path_cache/loaded_features_index.rb:92:in `register'
    from /Users/froop/.rvm/gems/ruby-3.0.0/gems/bootsnap-1.5.1/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:22:in `require_with_bootsnap_lfi'
    from /Users/froop/.rvm/gems/ruby-3.0.0/gems/bootsnap-1.5.1/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:31:in `require'
    from /Users/froop/.rvm/rubies/ruby-3.0.0/lib/ruby/gems/3.0.0/gems/activesupport-6.1.0/lib/active_support/dependencies.rb:332:in `block in require'
    from /Users/froop/.rvm/rubies/ruby-3.0.0/lib/ruby/gems/3.0.0/gems/activesupport-6.1.0/lib/active_support/dependencies.rb:299:in `load_dependency'
    from /Users/froop/.rvm/rubies/ruby-3.0.0/lib/ruby/gems/3.0.0/gems/activesupport-6.1.0/lib/active_support/dependencies.rb:332:in `require'
    from /Users/froop/.rvm/gems/ruby-3.0.0/gems/webdrivers-4.4.1/lib/webdrivers/geckodriver.rb:72:in `&lt;main&gt;'
    from /Users/froop/.rvm/gems/ruby-3.0.0/gems/bootsnap-1.5.1/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:23:in `require'
    from /Users/froop/.rvm/gems/ruby-3.0.0/gems/bootsnap-1.5.1/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:23:in `block in require_with_bootsnap_lfi'
    from /Users/froop/.rvm/gems/ruby-3.0.0/gems/bootsnap-1.5.1/lib/bootsnap/load_path_cache/loaded_features_index.rb:92:in `register'
    from /Users/froop/.rvm/gems/ruby-3.0.0/gems/bootsnap-1.5.1/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:22:in `require_with_bootsnap_lfi'
    from /Users/froop/.rvm/gems/ruby-3.0.0/gems/bootsnap-1.5.1/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:31:in `require'
    from /Users/froop/.rvm/rubies/ruby-3.0.0/lib/ruby/gems/3.0.0/gems/activesupport-6.1.0/lib/active_support/dependencies.rb:332:in `block in require'
    from /Users/froop/.rvm/rubies/ruby-3.0.0/lib/ruby/gems/3.0.0/gems/activesupport-6.1.0/lib/active_support/dependencies.rb:299:in `load_dependency'
    from /Users/froop/.rvm/rubies/ruby-3.0.0/lib/ruby/gems/3.0.0/gems/activesupport-6.1.0/lib/active_support/dependencies.rb:332:in `require'
    from /Users/froop/.rvm/gems/ruby-3.0.0/gems/webdrivers-4.4.1/lib/webdrivers.rb:4:in `&lt;main&gt;'
    from /Users/froop/.rvm/gems/ruby-3.0.0/gems/bootsnap-1.5.1/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:23:in `require'
    from /Users/froop/.rvm/gems/ruby-3.0.0/gems/bootsnap-1.5.1/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:23:in `block in require_with_bootsnap_lfi'
    from /Users/froop/.rvm/gems/ruby-3.0.0/gems/bootsnap-1.5.1/lib/bootsnap/load_path_cache/loaded_features_index.rb:92:in `register'
    from /Users/froop/.rvm/gems/ruby-3.0.0/gems/bootsnap-1.5.1/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:22:in `require_with_bootsnap_lfi'
    from /Users/froop/.rvm/gems/ruby-3.0.0/gems/bootsnap-1.5.1/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:31:in `require'
    from /Users/froop/.rvm/rubies/ruby-3.0.0/lib/ruby/3.0.0/bundler/runtime.rb:66:in `block (2 levels) in require'
    from /Users/froop/.rvm/rubies/ruby-3.0.0/lib/ruby/3.0.0/bundler/runtime.rb:61:in `each'
    from /Users/froop/.rvm/rubies/ruby-3.0.0/lib/ruby/3.0.0/bundler/runtime.rb:61:in `block in require'
    from /Users/froop/.rvm/rubies/ruby-3.0.0/lib/ruby/3.0.0/bundler/runtime.rb:50:in `each'
    from /Users/froop/.rvm/rubies/ruby-3.0.0/lib/ruby/3.0.0/bundler/runtime.rb:50:in `require'
    from /Users/froop/.rvm/rubies/ruby-3.0.0/lib/ruby/3.0.0/bundler.rb:174:in `require'
    from /Users/froop/Rails/froop_app/config/application.rb:7:in `&lt;top (required)&gt;'
    from /Users/froop/.rvm/gems/ruby-3.0.0/gems/spring-2.1.1/lib/spring/application.rb:92:in `require'
    from /Users/froop/.rvm/gems/ruby-3.0.0/gems/spring-2.1.1/lib/spring/application.rb:92:in `preload'
    from /Users/froop/.rvm/gems/ruby-3.0.0/gems/spring-2.1.1/lib/spring/application.rb:157:in `serve'
    from /Users/froop/.rvm/gems/ruby-3.0.0/gems/spring-2.1.1/lib/spring/application.rb:145:in `block in run'
    from /Users/froop/.rvm/gems/ruby-3.0.0/gems/spring-2.1.1/lib/spring/application.rb:139:in `loop'
    from /Users/froop/.rvm/gems/ruby-3.0.0/gems/spring-2.1.1/lib/spring/application.rb:139:in `run'
    from /Users/froop/.rvm/gems/ruby-3.0.0/gems/spring-2.1.1/lib/spring/application/boot.rb:19:in `&lt;top (required)&gt;'
    from &lt;internal:/Users/froop/.rvm/rubies/ruby-3.0.0/lib/ruby/3.0.0/rubygems/core_ext/kernel_require.rb&gt;:85:in `require'
    from &lt;internal:/Users/froop/.rvm/rubies/ruby-3.0.0/lib/ruby/3.0.0/rubygems/core_ext/kernel_require.rb&gt;:85:in `require'
    from -e:1:in `&lt;main&gt;'
  </code></pre>
  <p>I'm not at all sure what's causing this. Rails is up to date. Can anyone point me in the right direction?</p>