title: Yarn Build - Babel-loader issues with Storybook
body: <p>I have a new create react app project, using the typescript template:</p>
  <pre><code>yarn create react-app my-app --template typescript
  </code></pre>
  <p>To this, I have added Storybook with:</p>
  <pre><code>npx sb init
  </code></pre>
  <p>This has given me a working storybook instance, however, <code>yarn build</code> now errors.</p>
  <pre><code>$ react-scripts build
  
  There might be a problem with the project dependency tree.
  It is likely not a bug in Create React App, but something you need to fix locally.
  
  The react-scripts package provided by Create React App requires a dependency:
  
    &quot;babel-loader&quot;: &quot;8.1.0&quot;
  
  Don't try to install it manually: your package manager does it automatically.
  However, a different version of babel-loader was detected higher up in the tree:
  
    /home/michael/pgit/my-app/node_modules/babel-loader (version: 8.2.2)
  
  Manually installing incompatible versions is known to cause hard-to-debug issues.
  
  If you would prefer to ignore this check, add SKIP_PREFLIGHT_CHECK=true to an .env file in your project.
  That will permanently disable this message but you might encounter other issues.
  
  To fix the dependency tree, try following the steps below in the exact order:
  
    1. Delete package-lock.json (not package.json!) and/or yarn.lock in your project folder.
    2. Delete node_modules in your project folder.
    3. Remove &quot;babel-loader&quot; from dependencies and/or devDependencies in the package.json file in your project folder.
    4. Run npm install or yarn, depending on the package manager you use.
  
  In most cases, this should be enough to fix the problem.
  If this has not helped, there are a few other things you can try:
  
    5. If you used npm, install yarn (http://yarnpkg.com/) and repeat the above steps with it instead.
       This may help because npm has known issues with package hoisting which may get resolved in future versions.
  
    6. Check if /home/michael/pgit/my-app/node_modules/babel-loader is outside your project directory.
       For example, you might have accidentally installed something in your home folder.
  
    7. Try running npm ls babel-loader in your project folder.
       This will tell you which other package (apart from the expected react-scripts) installed babel-loader.
  
  If nothing else helps, add SKIP_PREFLIGHT_CHECK=true to an .env file in your project.
  That would permanently disable this preflight check in case you want to proceed anyway.
  
  P.S. We know this message is long but please read the steps above :-) We hope you find them helpful!
  </code></pre>
  <p>So <code>babel-loader</code> is not in any of my <code>package.json</code> files, and babel is all supposed to be handled by CRA (hence the warning not to add it yourself.)</p>
  <p>I can use the SKIP_PREFLIGHT_CHECK - but that's masking the potential conflict, what is the correct way to get the two libraries pre-requisites to play together?</p>