Ember-cli taking a long time to build after app migration - ember.js

Question

I recently migrated an ember app that I was compiling using bower to ember-cli. It had already grown pretty large, but I was running into issues with my current dev environment and ember-cli seems like the cleaner solution.
Unfortunately, after updating the files for the ember-cli interface, the build isn't working. I have left it running for 5 minutes at 100% CPU, and it reached two dots after Building.. and stopped.
I am using Sublime text, but I updated my preferences under http://www.ember-cli.com/#commonissues. I added broccoli-sass using npm and ember-data.model-fragments using ember install:addon. Below is my package.json
{
"name": "frontend",
"version": "0.0.0",
"description": "Small description for frontend goes here",
"private": true,
"directories": {
"doc": "doc",
"test": "tests"
},
"scripts": {
"start": "ember server",
"build": "ember build",
"test": "ember test"
},
"repository": "",
"engines": {
"node": ">= 0.10.0"
},
"author": "",
"license": "MIT",
"devDependencies": {
"broccoli-asset-rev": "^2.0.0",
"broccoli-sass": "git://github.com/aexmachina/broccoli-sass#sources-content",
"ember-cli": "0.1.11",
"ember-cli-6to5": "^3.0.0",
"ember-cli-app-version": "0.3.0",
"ember-cli-content-security-policy": "0.3.0",
"ember-cli-dependency-checker": "0.0.7",
"ember-cli-htmlbars": "^0.6.0",
"ember-cli-ic-ajax": "0.1.1",
"ember-cli-inject-live-reload": "^1.3.0",
"ember-cli-qunit": "0.3.0",
"ember-cli-uglify": "1.0.1",
"ember-data": "1.0.0-beta.14.1",
"ember-data-model-fragments": "0.2.7",
"ember-export-application-global": "^1.0.0",
"express": "^4.8.5",
"glob": "^4.0.5"
}
}
and here is my app file tree. I'm wondering if it has something to do with all the folders I added (objects, definitions, libraries, etc).
app
├── app.js
├── components
│   ├── dual-slider.js
│   ├── scroll-arrow.js
│   ├── single-slider.js
│   └── square-div.js
├── controllers
│   ├── application.js
│   ├── authentication
│   │   ├── login.js
│   │   └── signup.js
│   ├── demos
│   │   ├── derivatives.js
│   │   ├── integrals.js
│   │   └── revolutions.js
│   ├── flash.js
│   ├── index.js
│   ├── lessons
│   │   ├── index.js
│   │   ├── new
│   │   │   ├── create-step.js
│   │   │   ├── index.js
│   │   │   └── step.js
│   │   ├── new.js
│   │   ├── show
│   │   │   ├── index.js
│   │   │   └── step.js
│   │   └── show.js
│   └── subjects
│   ├── index.js
│   └── show.js
├── definitions
│   ├── animationKeys.js
│   ├── stepArray.js
│   └── typeKeys.js
├── helpers
│   ├── focus-input.js
│   └── slider-label-input.js
├── index.html
├── initializers
│   └── session-setup.js
├── libraries
│   └── mathAnimationLibrary
│   ├── dist
│   │   ├── display-library.js
│   │   └── vendor
│   │   ├── math.js
│   │   ├── three.js
│   │   ├── trackballControls.js
│   │   └── zgentilis_bold.typeface.js
│   └── src
│   ├── DisplayLibrary.js
│   └── functions
│   ├── create2DFunction.js
│   ├── createAxis.js
│   ├── createIntegralDisplay.js
│   ├── createRotationFunction.js
│   ├── createSurface.js
│   ├── mathEnvironment.js
│   └── showDerivative.js
├── mixins
│   └── animation.js
├── models
│   ├── animation-params.js
│   ├── animation.js
│   ├── choice.js
│   ├── equation-part.js
│   ├── equation.js
│   ├── explanation.js
│   ├── instruction.js
│   ├── lesson-step-type.js
│   ├── lesson-step.js
│   ├── lesson.js
│   ├── multiple-choice.js
│   ├── special-animation-params.js
│   ├── subject.js
│   └── user.js
├── objects
│   ├── flash-queue.js
│   ├── flash.js
│   └── session.js
├── router.js
├── routes
│   ├── index.js
│   ├── lessons
│   │   ├── index.js
│   │   ├── new
│   │   │   ├── create-step.js
│   │   │   ├── index.js
│   │   │   └── step.js
│   │   ├── new.js
│   │   ├── show
│   │   │   ├── index.js
│   │   │   └── step.js
│   │   └── show.js
│   ├── logout.js
│   └── subjects
│   ├── index.js
│   └── show.js
├── serializers
│   ├── application.js
│   └── lesson.js
├── styles
│   ├── app.scss
│   ├── reset.css
│   └── sass
│   ├── authentication
│   │   └── authentication.scss
│   ├── colors.scss
│   ├── components
│   │   ├── scroll-arrow.scss
│   │   ├── slider.scss
│   │   └── square-div.scss
│   ├── helpers
│   │   └── flash.scss
│   ├── lessons
│   │   ├── multiple-choice.scss
│   │   └── show.scss
│   ├── main.scss
│   ├── mixins.scss
│   └── root
│   ├── demos.scss
│   ├── header.scss
│   └── index.scss
├── templates
│   ├── about
│   │   └── index.hbs
│   ├── application.hbs
│   ├── backend.hbs
│   ├── components
│   │   ├── dual-slider.hbs
│   │   ├── scroll-arrow.hbs
│   │   ├── single-slider.hbs
│   │   └── square-div.hbs
│   ├── demos
│   │   ├── derivatives.hbs
│   │   ├── index.hbs
│   │   ├── integrals.hbs
│   │   └── revolutions.hbs
│   ├── index.hbs
│   ├── lessons
│   │   ├── equationViewer.hbs
│   │   ├── index.hbs
│   │   ├── multipleChoice.hbs
│   │   ├── new
│   │   │   ├── createStep.hbs
│   │   │   ├── index.hbs
│   │   │   └── step.hbs
│   │   ├── new.hbs
│   │   ├── show
│   │   │   ├── index.hbs
│   │   │   └── step.hbs
│   │   └── show.hbs
│   ├── login.hbs
│   ├── shared
│   ├── signup.hbs
│   └── subjects
│   ├── index.hbs
│   └── show.hbs
└── views
├── demos
│   ├── derivatives.js
│   ├── integrals.js
│   └── revolutions.js
├── flash.js
└── lessons
├── equationViewer.js
└── multipleChoice.js
It's also possible that I missed an import/export somewhere in the file transfer. Would this fail silently as I am seeing or would it raise an error?
I appreciate any insight that you might have.

Answer 1

So apparently there is already some discussion about this on the issues board. Particularly, ember-cli-6to5 is apparently messing with build times in the recent version of ember-cli. After removing that component (you lose functionality aside from modules) it builds much faster. See this discussion for more detail https://github.com/ember-cli/ember-cli/issues/3136.