Ember partial memory leak

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  show: true,
  version: Ember.VERSION,
  actions: {
    toggle() {
      this.toggleProperty('show');
      this.set('glimmerEnvStrings', Ember.getOwner(this).lookup('service:-glimmer-environment').constants.strings.length);
  	},
  }
});

templates.-partial.hbs

My Partial

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<button {{action "toggle"}}>show/hide</button>
<br><br>
{{#if show}}
{{ partial "partial" }}
{{/if}}
<br>
<br>
<b>Ember Version</b>: {{version}}
<br>
<br>
<b>glimmerEnv.constants.strings.length</b>: {{glimmerEnvStrings}}

twiddle.json

{
  "version": "0.12.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "release",
    "ember-template-compiler": "release",
    "ember-testing": "release",
    "ember-data": "2.12.1"
  },
  "addons": {}
}