The new feature that allows you to put environment variables in .ember-cli has some very surprising side effects:

1. At runtime, require('your-app/config/environment').default.environment changes from a string like "development" to a POJO containing the settings from your .ember-cli.

2. Custom ember-cli commands that previously accepted their own option named environment are now getting stomped with the settings from .ember-cli. Here is an example of a command that breaks if you try to use the new feature.