Not using the Expo fork of react-native

If you create a react native app with the command from the getting started page: $create-react-native-app AwesomeProject then the package.json file has the following dependencies:

"dependencies": {
  "expo": "^20.0.0",
  "react": "16.0.0-alpha.12",
  "react-native": "^0.47.0"
}

If you create an app directly in the Expo XDE, you will see in the package.json, they use a fork of react-native:

"dependencies": {
  "expo": "^20.0.0",
  "react": "16.0.0-alpha.12",
  "react-native": "https://github.com/expo/react-native/archive/sdk-20.0.0.tar.gz"
},

Changing the react-native module path to https://github.com/expo/react-native/archive/sdk-20.0.0.tar.gz and running npm install will fix the problem.