Undefined closure actions

application.controller.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName:'Ember Twiddle',
  
  actions: {
    handleClickOnA: function () {
      alert('a was clicked');
    }
  }
});

application.template.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{my-thing click-a=(action "handleClickOnA")}}
<br>
<br>

my-thing.component.js

import Ember from 'ember';

export default Ember.Component.extend({
});

my-thing.template.hbs

<button onclick={{action (action attrs.click-a)}}>Button A</button>

<br><br>

Button B is commented out. Uncomment it and the code will break with error <strong style="background-color:hsl(60, 100%, 92%);">"Cannot read property 'INVOKE [id=...]' of null"</strong>.

{{!--
<button onclick={{action (action attrs.click-b)}}>Button B</button>
--}}

twiddle.json

{
  "version": "0.4.17",
  "EmberENV": {
    "FEATURES": {}
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.2.0/ember.debug.js",
    "ember-data": "https://cdnjs.cloudflare.com/ajax/libs/ember-data.js/2.2.0/ember-data.js",
    "ember-template-compiler": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.2.0/ember-template-compiler.js"
  }
}