title: Using Yarn in Sage Wordpress Starter Template
body: <p>Hello I recently started using sage again after a long time and a lot of things seem to have changed for me.  I had to install yarn but when I tried running the command <code>yarn run build</code> I got:</p>
  
  <pre><code>λ yarn run build
  yarn run v0.20.3
  $ webpack --progress --config assets/build/webpack.config.js
  F:\www\xxxxxx\wp-content\themes\23022017\node_modules\copy-globs-webpack-plugin\index.js:101
  const { promisify } = __webpack_require__(0);
        ^
  
  SyntaxError: Unexpected token {
      at exports.runInThisContext (vm.js:53:16)
      at Module._compile (module.js:414:25)
      at Object.Module._extensions..js (module.js:442:10)
      at Module.load (module.js:356:32)
      at Function.Module._load (module.js:311:12)
      at Module.require (module.js:366:17)
      at require (module.js:385:17)
      at Object.&lt;anonymous&gt; (F:\www\xxxxxx\wp-content\themes\23022017\assets\build\webpack.config.js:10:25)
      at Module._compile (module.js:435:26)
      at Object.Module._extensions..js (module.js:442:10)
  error Command failed with exit code 1.
  info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
  </code></pre>
  
  <p>Now I have already successfully run the following commands in my terminal:</p>
  
  <pre><code>composer self-update
  composer update
  npm install
  yarn
  </code></pre>
  
  <p>I am new to yarn and webpack so I can't even begin to understand what I'm doing wrong here or how to fix it.</p>
  
  <p><strong>OS:</strong> Windows 10</p>
  
  <p><strong>NodeJS:</strong> 4.8.0</p>