EC fetch bug

components.fetch-result.js

import Ember from 'ember';
import {inject as service} from '@ember/service';

export default Ember.Component.extend({
  fetchTask: service(),
  
 
  init() {
    this._super(...arguments);
    // this.fetchResult = this.fetchTask.doFetch.perform();
    this.fetchResult = this.fetchTask.doAsyncFetch();
  }
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle'
});

services.fetch-task.js

import Ember from 'ember';
import { task } from 'ember-concurrency';
import fetch from 'fetch';

export default Ember.Service.extend({
  doFetch: task(function * () {
    try {
      const res = yield fetch('https://api.github.com');
      const json = yield res.json();
      
      return json;
      
    } catch(err) {
      throw new Error(err.message); 
    }
  }),
  
  async doAsyncFetch() {
    try {
      const res = await fetch('https://api.github.com');
  debugger
      const json = await res.json();
  debugger;
      
      return json;
      
    } catch(err) {
      throw new Error(err.message); 
    }
  },
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
<p>Fetch Result</p>
{{fetch-result}}


{{outlet}}
<br>
<br>

templates.components.fetch-result.hbs

{{await this.fetchResult}}

twiddle.json

{
  "version": "0.15.0",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "3.2.2",
    "ember-template-compiler": "3.2.2",
    "ember-testing": "3.2.2"
  },
  "addons": {
    "ember-data": "3.2.0",
    "ember-concurrency": "0.8.19",
    "ember-fetch": "5.0.0",
    "ember-promise-helpers": "1.0.6"
  }
}