ember-cli: "Installing packages for tooling via npm" just hangs there

To recreate:

Simply type ember new app-name in the terminal and it always stalls on npm

The output:

installing app
  create .bowerrc
  create .editorconfig
  create .ember-cli
  create .jshintrc
  create .travis.yml
  create .watchmanconfig
  create README.md
  create app/app.js
  create app/components/.gitkeep
  create app/controllers/.gitkeep
  create app/helpers/.gitkeep
  create app/index.html
  create app/models/.gitkeep
  create app/resolver.js
  create app/router.js
  create app/routes/.gitkeep
  create app/styles/app.css
  create app/templates/application.hbs
  create app/templates/components/.gitkeep
  create bower.json
  create config/environment.js
  create ember-cli-build.js
  create .gitignore
  create package.json
  create public/crossdomain.xml
  create public/robots.txt
  create testem.js
  create tests/.jshintrc
  create tests/helpers/destroy-app.js
  create tests/helpers/module-for-acceptance.js
  create tests/helpers/resolver.js
  create tests/helpers/start-app.js
  create tests/index.html
  create tests/integration/.gitkeep
  create tests/test-helper.js
  create tests/unit/.gitkeep
  create vendor/.gitkeep
Successfully initialized git.
⠋ Installing packages for tooling via npm

And it just hangs there for longer than I could wait. Let me know if you need more info.

Output from ember version --verbose:

$ ember -v --verbose
ember-cli: 2.5.1
http_parser: 2.6.2
node: 5.7.0
v8: 4.6.85.31
uv: 1.8.0
zlib: 1.2.8
ares: 1.10.1-DEV
icu: 56.1
modules: 47
openssl: 1.0.2f
os: darwin x64

Some additional info:

OS: OSX Yosemite 10.10.5 (14F1713)
$ npm -v
3.6.0