title: React failing to compile postcss, yamldumper.js
body: <p>On windows When trying to compile a freshly made react app from "create-react-app" I am receiving a compile error. Not sure where the unexpected token is coming from. The error is referring to a unexpected token in index.css from the creation of create-react-app.</p>
  
  <p>index.css:</p>
  
  <pre><code>body {
    margin: 0;
    padding: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Roboto", "Oxygen",
      "Ubuntu", "Cantarell", "Fira Sans", "Droid Sans", "Helvetica Neue",
      sans-serif;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
  }
  
  code {
    font-family: source-code-pro, Menlo, Monaco, Consolas, "Courier New",
      monospace;
  }
  </code></pre>
  
  <p>Output below from install and run:</p>
  
  <pre><code>D:\Projects\reactsites&gt;cd Test2
  
  D:\Projects\reactsites\Test2&gt;npx create-react-app derpsocial
  
  Creating a new React app in D:\Projects\reactsites\Test2\derpsocial.
  
  Installing packages. This might take a couple of minutes.
  Installing react, react-dom, and react-scripts...
  
  yarn add v1.9.4
  [1/4] Resolving packages...
  [2/4] Fetching packages...
  [-----------------------------------------------------------------------] 0/1283(
  node:3584) [DEP0005] DeprecationWarning: Buffer() is deprecated due to security and usability issues. Please use the Buffer.alloc(), Buffer.allocUnsafe(), or Buffer.from() methods instead.
  info fsevents@1.2.4: The platform "win32" is incompatible with this module.
  info "fsevents@1.2.4" is an optional dependency and failed compatibility check. Excluding it from installation.
  [3/4] Linking dependencies...
  [4/4] Building fresh packages...
  
  success Saved lockfile.
  warning Your current version of Yarn is out of date. The latest version is "1.12.
  3", while you're on "1.9.4".
  info To upgrade, download the latest installer at "https://yarnpkg.com/latest.msi".
  success Saved 6 new dependencies.
  info Direct dependencies
  ├─ react-dom@16.6.3
  ├─ react-scripts@2.1.1
  └─ react@16.6.3
  info All dependencies
  ├─ babel-preset-react-app@6.1.0
  ├─ react-dev-utils@6.1.1
  ├─ react-dom@16.6.3
  ├─ react-error-overlay@5.1.0
  ├─ react-scripts@2.1.1
  └─ react@16.6.3
  Done in 236.47s.
  
  Initialized a git repository.
  
  Success! Created derpsocial at D:\Projects\reactsites\Test2\derpsocial
  Inside that directory, you can run several commands:
  
    yarn start
      Starts the development server.
  
    yarn build
      Bundles the app into static files for production.
  
    yarn test
      Starts the test runner.
  
    yarn eject
      Removes this tool and copies build dependencies, configuration files
      and scripts into the app directory. If you do this, you can't go back!
  
  We suggest that you begin by typing:
  
    cd derpsocial
    yarn start
  
  Happy hacking!
  
  D:\Projects\reactsites\Test2&gt;cd derpsocial
  
  D:\Projects\reactsites\Test2\derpsocial&gt;yarn start
  yarn run v1.9.4
  $ react-scripts start
  Failed to compile.
  
  ./src/index.css (./node_modules/css-loader??ref--6-oneOf-3-1!./node_modules/postcss-loader/src??postcss!./src/index.css)
  D:\Projects\reactsites\Test2\derpsocial\node_modules\js-yaml\lib\js-yaml\dumper.js:275
    return result;
    ^^^^^^
  
  SyntaxError: Unexpected token return
  
  D:\Projects\reactsites\Test2\derpsocial&gt;npm -version
  6.4.1
  
  D:\Projects\reactsites\Test2\derpsocial&gt;node -v
  v10.13.0
  
  D:\Projects\reactsites\Test2\derpsocial&gt;
  </code></pre>
  
  <p>I've tried to update all packages, even took out the css from index.css with the same error present. Reinstalled node and npm.</p>