ionic build --prod fails for firebase(even with blank app)

[ketanyekale]

Description:
After adding firebase(not angularfire2) ionic build --prod hangs after copy finished step
The same work perfectly without --prod option. I'm using firebase auth, database and messaging in by PWA + Mobile Apps. All the features works perfectly in non-prod mode.

I even tried setting --max-old-space-size to 4GB but it still doesn't work.

Steps to Reproduce:
I have tried the same for blank ionic app.

1. Create new blank ionic app

ionic start blank1 blank

2. Need to add platform as ionic build needs atleast one platform

ionic cordova add platform android

3. build without --prod will be successful
   ionic build

4. build with --prod will also be successful
   ionic build --prod

5. Now add firebase
   npm i -s firebase

6. add firebase imports
   As mentioned at https://www.npmjs.com/package/firebase#include-only-the-features-you-need
   I have used the below code to import firebase app, auth database and messaging:

// This import loads the firebase namespace along with all its type information.
import firebase from 'firebase/app';

// These imports load individual services into the firebase namespace.
import 'firebase/auth';
import 'firebase/database';
import 'firebase/messaging';

I've added these imports in home.ts as:

import { Component } from '@angular/core';
import { NavController } from 'ionic-angular';
// This import loads the firebase namespace along with all its type information.
import firebase from 'firebase/app';

// These imports load individual services into the firebase namespace.
import 'firebase/auth';
import 'firebase/database';
import 'firebase/messaging';
@Component({
  selector: 'page-home',
  templateUrl: 'home.html'
})
export class HomePage {
  ts: any ='';
  constructor(public navCtrl: NavController) {
    this.ts = firebase.database.ServerValue.TIMESTAMP;// To avoid unnecessary warning: unused import firebase
  }
}

7. build without --prod will be successful
   ionic build

8. build with --prod will now fail
   ionic build --prod

Output:

c:\xampp\htdocs\blank1>ionic build --prod
Running app-scripts build: --prod
[20:11:41]  build prod started ...
[20:11:41]  clean started ...
[20:11:41]  clean finished in less than 1 ms
[20:11:41]  copy started ...
[20:11:41]  deeplinks started ...
[20:11:42]  deeplinks finished in 32 ms
[20:11:42]  ngc started ...
[20:11:50]  ngc finished in 8.87 s
[20:11:50]  preprocess started ...
[20:11:50]  preprocess finished in less than 1 ms
[20:11:50]  webpack started ...
[20:11:51]  copy finished in 9.42 s

My ionic info:

c:\xampp\htdocs\blank1>ionic info

cli packages: (C:\Users\Desk06\AppData\Roaming\npm\node_modules)

    @ionic/cli-utils  : 1.19.2
    ionic (Ionic CLI) : 3.20.0

global packages:

    cordova (Cordova CLI) : 8.0.0

local packages:

    @ionic/app-scripts : 3.1.10
    Cordova Platforms  : android 7.0.0
    Ionic Framework    : ionic-angular 3.9.2

System:

    Android SDK Tools : 26.1.1
    Node              : v8.11.1
    npm               : 6.0.1
    OS                : Windows 10

Environment Variables:

    ANDROID_HOME : E:\android_sdks

Misc:

    backend : pro

Other Information:

c:\xampp\htdocs\blank1>ionic build
Running app-scripts build:
[20:03:52]  build dev started ...
[20:03:52]  clean started ...
[20:03:52]  clean finished in 16 ms
[20:03:52]  copy started ...
[20:03:53]  deeplinks started ...
[20:03:53]  deeplinks finished in 15 ms
[20:03:53]  transpile started ...
[20:03:57]  transpile finished in 4.26 s
[20:03:57]  preprocess started ...
[20:03:57]  preprocess finished in 1 ms
[20:03:57]  webpack started ...
[20:03:57]  copy finished in 4.48 s
[20:04:04]  webpack finished in 6.71 s
[20:04:04]  sass started ...
Without `from` option PostCSS could generate wrong source map and will not find Browserslist config. Set it to CSS file path or to `undefined` to prevent this warning.
[20:04:05]  sass finished in 1.48 s
[20:04:05]  postprocess started ...
[20:04:05]  postprocess finished in 15 ms
[20:04:05]  lint started ...
[20:04:05]  build dev finished in 12.71 s
> ionic cordova prepare --no-build
> cordova prepare
Android Studio project detected


[20:04:11]  lint finished in 6.09 s

c:\xampp\htdocs\blank1>ionic build --prod
Running app-scripts build: --prod
[20:04:28]  build prod started ...
[20:04:28]  clean started ...
[20:04:28]  clean finished in less than 1 ms
[20:04:28]  copy started ...
[20:04:28]  deeplinks started ...
[20:04:28]  deeplinks finished in 16 ms
[20:04:28]  ngc started ...
[20:04:37]  ngc finished in 8.62 s
[20:04:37]  preprocess started ...
[20:04:37]  preprocess finished in less than 1 ms
[20:04:37]  webpack started ...
[20:04:37]  copy finished in 9.10 s
[20:05:06]  webpack finished in 28.59 s
[20:05:06]  uglify started ...
[20:05:06]  sass started ...
Without `from` option PostCSS could generate wrong source map and will not find Browserslist config. Set it to CSS file path or to `undefined` to prevent this warning.
[20:05:07]  sass finished in 1.73 s
[20:05:07]  cleancss started ...
[20:05:10]  cleancss finished in 2.50 s
[20:05:21]  uglify finished in 15.87 s
[20:05:21]  postprocess started ...
[20:05:21]  postprocess finished in less than 1 ms
[20:05:21]  lint started ...
[20:05:21]  build prod finished in 53.26 s
> ionic cordova prepare --no-build
> cordova prepare
Android Studio project detected


[20:05:28]  lint finished in 6.48 s

c:\xampp\htdocs\blank1>npm i -s firebase
[grpc] Success: "c:\xampp\htdocs\blank1\node_modules\grpc\src\node\extension_binary\node-v57-win32-x64-unknown\grpc_node.node" is installed via remote
+ firebase@5.1.0
added 110 packages from 59 contributors in 42.995s
[!] 1 vulnerability found [3788 packages audited]
    Severity: 1 Low
    Run `npm audit` for more detail


c:\xampp\htdocs\blank1>ionic build
Running app-scripts build:
[20:10:52]  build dev started ...
[20:10:52]  clean started ...
[20:10:52]  clean finished in 16 ms
[20:10:52]  copy started ...
[20:10:53]  deeplinks started ...
[20:10:53]  deeplinks finished in 31 ms
[20:10:53]  transpile started ...
[20:10:57]  transpile finished in 4.59 s
[20:10:57]  preprocess started ...
[20:10:57]  preprocess finished in less than 1 ms
[20:10:57]  webpack started ...
[20:10:57]  copy finished in 4.86 s
[20:11:04]  webpack finished in 7.35 s
[20:11:04]  sass started ...
Without `from` option PostCSS could generate wrong source map and will not find Browserslist config. Set it to CSS file path or to `undefined` to prevent this warning.
[20:11:06]  sass finished in 1.81 s
[20:11:06]  postprocess started ...
[20:11:06]  postprocess finished in 47 ms
[20:11:06]  lint started ...
[20:11:06]  build dev finished in 14.10 s
> ionic cordova prepare --no-build
> cordova prepare
[20:11:13]  lint finished in 6.97 s
Android Studio project detected



c:\xampp\htdocs\blank1>ionic build --prod
Running app-scripts build: --prod
[20:11:41]  build prod started ...
[20:11:41]  clean started ...
[20:11:41]  clean finished in less than 1 ms
[20:11:41]  copy started ...
[20:11:41]  deeplinks started ...
[20:11:42]  deeplinks finished in 32 ms
[20:11:42]  ngc started ...
[20:11:50]  ngc finished in 8.87 s
[20:11:50]  preprocess started ...
[20:11:50]  preprocess finished in less than 1 ms
[20:11:50]  webpack started ...
[20:11:51]  copy finished in 9.42 s

[ljieyao]

I have the same issue. plz help.

Same Issue also. Please fix this.