title: I just added var React = require('react-native'); and my whole build failed
body: <p>I just added</p>
  
  <pre><code>var React = require('react-native');
  </code></pre>
  
  <p>to my index.ios.js file but when I reload my React Native application, this
  comes up:</p>
  
  <p><a href="http://i.stack.imgur.com/iODOm.png" rel="nofollow">It says React is read-only?!</a></p>
  
  <p>So I tried to change the permissions on the react-native module by doing</p>
  
  <pre><code>sudo chmod -R 777 ExampleProject
  sudo chmod -R 777 ExampleProject/node_modules/react-native
  </code></pre>
  
  <p>but it still doesn't work. What did I do wrong?</p>
  
  <hr>
  
  <p>This is the full source code of my index.ios.js file:</p>
  
  <pre><code> * Sample React Native App
   * https://github.com/facebook/react-native
   */
   'use strict';
  
   var React = require('react-native');
  
   import React, {
     AppRegistry,
     Component,
     StyleSheet,
     Text,
     View
   } from 'react-native';
  
   class Logbook extends Component {
     render() {
     return (
     &lt;View style={styles.container}&gt;
      &lt;Text style={styles.welcome}&gt;
        Welcome to React Native!
      &lt;/Text&gt;
      &lt;Text style={styles.instructions}&gt;
        To get started, edit index.ios.js
      &lt;/Text&gt;
      &lt;Text style={styles.instructions}&gt;
        Press Cmd+R to reload,{'\n'}
        Cmd+D or shake for dev menu
      &lt;/Text&gt;
    &lt;/View&gt;
    );
    }
    }
  
   const styles = StyleSheet.create({
   container: {
   flex: 1,
   justifyContent: 'center',
   alignItems: 'center',
   backgroundColor: '#F5FCFF',
   },
   welcome: {
   fontSize: 20,
   textAlign: 'center',
   margin: 10,
   },
   instructions: {
   textAlign: 'center',
   color: '#333333',
   marginBottom: 5,
   },
   });
  
   AppRegistry.registerComponent('Logbook', () =&gt; Logbook);
  </code></pre>