How to make staging environment for Ember-CLI?

There are development, test and production environments in Ember CLI. I have test and production server. And I need to make build on test server like on production but with another environment configs. But test env in Ember CLI used for automatic tests.

I tried to call ember build --environment development on test server with next options in ember-cli-build.js file:

var app = new EmberApp(defaults, {
   // Add options here
   fingerprint: {
     prepend: 'http://ift.tt/2nvEkMo',
     enabled: true
   }
});

But I got error:

The Broccoli Plugin: [AssetRewrite] failed with:
TypeError: Cannot read property '2' of null
.....
The broccoli plugin was instantiated at:
.....

What is right way to build ember application on test server?