ember.js - Debugging Rails 3.2 failing to precompile ember-rails 0.19 -

looking way determine in code or in ember-rails/ember-rails-source error coming from. using rails 3.2 , latest ember-rails 0.19. when precompile assets failure:

unexpected token: operator (!) (line: 16, col: 178179, pos: 178546)  error     @ new js_parse_error (<eval>:3096:22)     @ js_error (<eval>:3104:15)     @ croak (<eval>:3557:17)     @ token_error (<eval>:3564:17)     @ unexpected (<eval>:3570:17)     @ object.semicolon [as 1] (<eval>:3590:51)     @ prog1 (<eval>:4133:29)     @ simple_statement (<eval>:3726:35)     @ <eval>:3634:35     @ block_ (<eval>:3822:32)   (in /users/sjustin/development/my-app/app/assets/javascripts/application.js.coffee) 

i've been able destructively assets precompile removing ember sprockets reference, #= require ember in application.js.coffee:

#= require jquery #= require jquery_ujs #= require ember #= require ember-data #= require_self #= require my-app  window.myapp = ember.application.create() 

but breaks app. if run app locally without precompiling don't errors rails or javascript console.

which javascript runtime (e.g. therubyracer, execjs, nodejs) using? have tried switch it? i'd recommend using node (especially if you're running multiple apps on single server), because don't have add gem if node installed.