Basic Ember app not working with default adapter

Here is the source code.

I'm running Ember-CLI from the master branch of the git repo (currently version 2.2.0-beta.1-master-e803ac7fa6) and linking via npm. This should be using versions 2.2.0 of Ember and Ember Data. In the middle of the basic tutorial, I hit an issue with Mirage and Ember Data. Without explicitly creating an application adapter, the app fails. There is a 404 error being thrown on the route that should be handled by Mirage, as well as numerous Adapter errors. No errors are shown during ember serve.

After running ember g adapter application, the app loaded in the browser but there was still an error because this generated a RESTAdapter instead of the preferred JSONAPIAdapter. After manually switching to the JSONAPIAdapter, everything is fine.

Is this an issue with Ember-CLI still using an old version of Ember Data somehow?