Cannot find type definition file for 'zen-observable'


#1

This Bug is a starting Bug that must be fixed at the nearest delay.

> ionic start app0 aws // aws is a default starting app in Ionic3 
> cd app0
> ionic serve

[app-scripts] [16:44:12]  typescript: node_modules/aws-amplify/lib/PubSub/Providers/MqttOverWSProvider.d.ts, line: 2 
[app-scripts]             Cannot find type definition file for 'zen-observable'. 
[app-scripts]        L1:  import { Client } from 'paho-mqtt';
[app-scripts]        L2:  import * as Observable from 'zen-observable';
[app-scripts]        L3:  import { AbstractPubSubProvider } from './PubSubProvider';
[app-scripts] [16:44:12]  typescript: node_modules/aws-amplify/lib/PubSub/Providers/PubSubProvider.d.ts, line: 1 
[app-scripts]             Cannot find type definition file for 'zen-observable'. 
[app-scripts]        L1:  import * as Observable from 'zen-observable';
[app-scripts]        L2:  import { PubSubProvider, ProvidertOptions } from '../types';
[app-scripts]             Cannot find type definition file for 'zen-observable'. 
[app-scripts] [16:44:12]  typescript: node_modules/aws-amplify/lib/PubSub/PubSub.d.ts, line: 1 
[app-scripts]        L1:  import '../Common/Polyfills';       
[app-scripts]        L2:  import * as Observable from 'zen-observable';
[app-scripts] [16:44:12]  typescript: node_modules/aws-amplify/lib/PubSub/types/Provider.d.ts, line: 1 
[app-scripts]             Cannot find type definition file for 'zen-observable'. 
[app-scripts]        L1:  import * as Observable from 'zen-observable';
[app-scripts]        L2:  import { ProvidertOptions } from './PubSub';

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> 
> Ionic:
> 
>    ionic (Ionic CLI) : 4.3.1
> 
> System:
> 
>    NodeJS : v8.9.4
>    npm    : 6.4.1
>    OS     : Linux 4.13