@expo/vector-icons not loaded when running from subfolder

I’m trying to use create-react-native-app with expo in a monorepo setup. When I start the app from a subfolder and import @expo/vector-icons I get an error that the font family is missing.

"fontFamily" 'material' is not a system font and has not been loaded through Expo.Font.loadAsync.

If I start the app in the main src/ folder the icons load fine. I’ve configured my rn-cli.config.js

My project is setup like a monorepo so that I can have multiple native apps in the repo.

src/
  MainApp.js
  package.json
  app/App.js 
  app/app.json
  app/package.json
  app/rn-cli.config.js
  ...

I’ve tried all various combos of install @expo/vector-icons in the subfolder package.json, but that didn’t help. I’ve tried setting "assetExts": ["ttf"] in the app.json file.

app/App.js

export { default } from "../MainApp";

app/app.json

{
  "expo": {
    "sdkVersion": "22.0.0",
    "react": "16.0.0-beta.5"
  }
}

app/package.json

{
  "private": true,
  "main": "./node_modules/react-native-scripts/build/bin/crna-entry.js",
  "scripts": {
    "native": "react-native-scripts start"
  },
  "dependencies": {
    "@expo/vector-icons": "^6.2.1",
    "expo": "^22.0.0",
    "react-native": "^0.49.0",
    "react-native-scripts": "1.7.0"
  }
}

app/rn-cli.config.js

const blacklist = require("metro-bundler/src/blacklist");
const path = require("path");

const roots = [process.cwd(), path.resolve(__dirname, "..")];

const config = {
  getProjectRoots: () => roots,

  /**
   * Specify where to look for assets that are referenced using
   * `image!<image_name>`. Asset directories for images referenced using
   * `./<image.extension>` don't require any entry in here.
   */
  getAssetRoots: () => roots,

  /**
   * Returns a regular expression for modules that should be ignored by the
   * packager on a given platform.
   */
  getBlacklistRE: () =>
    blacklist([
      // Ignore the local react-native so that we avoid duplicate modules
      /\/app\/node_modules\/react-native\/.*/
    ])
};

module.exports = config;

package.json

{
  "name": "react-native-app",
  "version": "0.1.0",
  "private": true,
  "devDependencies": {
    "react-native-scripts": "1.7.0"
  },
  "scripts": {
    "native": "cd app && yarn native"
  },
  "dependencies": {
    "@expo/vector-icons": "^6.2.1",
    "expo": "^22.0.0",
    "react": "16.0.0-beta.5",
    "react-native": "^0.49.0"
  }
}

MainApp.js

import React from "react";
import { StyleSheet, Text, View } from "react-native";
import MaterialIcons from "react-native-vector-icons/MaterialIcons";

export default class App extends React.Component {
  render() {
    return (
      <View style={styles.container}>
        <Text>Open up App.js to start working on your app!</Text>
        <Text>Changes you make will automatically reload.</Text>
        <Text>Shake your phone to open the developer menu.</Text>
        <MaterialIcons name="search" color="black" size={32} />
        <MaterialIcons name="location-searching" color="black" size={32} />
      </View>
    );
  }
}
const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: "#fff",
    alignItems: "center",
    justifyContent: "center"
  }
});