title: Ruby on Rails error: superclass mismatch for class StringIO (TypeError)
body: <p>I am getting an error while creating a ruby on rails project. In command, I created a new project by typing <code>rails new club</code>, then <code>bundle</code>. Now, when I try to create my models and controllers by typing and entering <code>rails g resource Club name</code>, I get this error: <code>superclass mismatch for class StringIO (TypeError)</code>.</p>
  <pre><code>gems/bootsnap-1.9.1/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:23:
  in `require': superclass mismatch for class StringIO (TypeError)
  </code></pre>
  <p>I don't even has a class named <code>StringIO</code>, so I'm not sure where it came from.</p>
  <ul>
  <li>ruby version: 2.6.8</li>
  <li>rails: 6.1.4.1</li>
  </ul>