I'm using Phantom JS 1.9.8 on OSX 10.10 but I've had the following problem and it may help you to know this.
In the application I'm using, the ENV.baseUrl flag is set to "/app-name" (the default being - '/') and I have that exact same behaviour. The test builds but does not go any further.
If I change my ENV.baseUrl to be '/', phantom runs the tests. Acceptance tests fail (I presume because of the different URL, but all unit tests pass). However, when I do this... running the tests in a real browser stops working (because it cannot find the resources - CSS,JS - anymore), I've tried changing the tests/index.html page to have a the correct reference to the scripts (/app-name/css/... etc...) and I got back the to running the tests in the browser, but phantom stopped working.
The same tests run fine in an "empty ember-cli project" where I copied my models, controllers and test to that project. Meaning that the difference between the two projects is basically environment configuration.
I've found these issues
Ember Issue 891 , Ember Issue 1003
Which seem to be related to the situation but both are closed for some time. I've been investigating this issue for almost a week now and can't seem to get tests running in the browser AND via ember test
.