Ionic pro build fails on import functions from firebase/app

Hi there

I am able to build locally using ionic cordova build android, but getting the following build error on ionic pro:

import { app, auth, database, firestore, functions, messaging, storage } from ‘firebase/app’
typescript: node_modules/@angular/fire/firebase.app.module.d.ts, line: 2

Package.json extract…

"@angular/common": "5.2.11",
"@angular/compiler": "5.2.11",
"@angular/compiler-cli": "5.2.11",
"@firebase/app": "^0.1.10",
"angularfire2": "^5.0.0-rc.6.0",
"cordova-android": "~7.0.0",
"firebase": "^4.12.1",
"ionic-angular": "3.9.2",
"rxjs": "5.5.11",

Any suggestions?