Problem with Sass on Heroku - Rails 3.1 rc6

heroku run console

-----> Compiled slug size is 24.9MB
-----> Launching... done, v7
       http://hollow-autumn-208.herokuapp.com deployed to Heroku

To [email protected]:hollow-autumn-208.git
   abce1c0..eb33c6a  master -> master
<lsappsin30days/app6ruby-1.9.2-head@railsRC6 [app6 (master)]$ heroku run console
Running console attached to terminal... up, run.2
Sprockets::Environment#static_root is deprecated
/app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.0.rc6/lib/rails/railtie/configuration.rb:78:in `method_missing': undefined method `sass' for #<Rails::Application::Configuration:0x00000001bec278> (NoMethodError)
	from /app/vendor/bundle/ruby/1.9.1/bundler/gems/compass-f23bf58e8db8/lib/compass/configuration/helpers.rb:82:in `block in configure_rails!'
	from /app/vendor/bundle/ruby/1.9.1/bundler/gems/compass-f23bf58e8db8/lib/compass/configuration/helpers.rb:81:in `each'
	from /app/vendor/bundle/ruby/1.9.1/bundler/gems/compass-f23bf58e8db8/lib/compass/configuration/helpers.rb:81:in `configure_rails!'
	from /app/vendor/bundle/ruby/1.9.1/bundler/gems/compass-f23bf58e8db8/lib/compass/app_integration/rails/actionpack31/railtie.rb:47:in `block in <class:Railtie>'
	from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.0.rc6/lib/rails/initializable.rb:25:in `instance_exec'
	from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.0.rc6/lib/rails/initializable.rb:25:in `run'
	from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.0.rc6/lib/rails/initializable.rb:50:in `block in run_initializers'
	from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.0.rc6/lib/rails/initializable.rb:49:in `each'
	from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.0.rc6/lib/rails/initializable.rb:49:in `run_initializers'
	from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.0.rc6/lib/rails/application.rb:92:in `initialize!'
	from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.0.rc6/lib/rails/railtie/configurable.rb:30:in `method_missing'
	from /app/config/environment.rb:5:in `<top (required)>'
	from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.0.rc6/lib/rails/application.rb:78:in `require'
	from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.0.rc6/lib/rails/application.rb:78:in `require_environment!'
	from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.0.rc6/lib/rails/commands.rb:39:in `<top (required)>'
	from script/rails:6:in `require'
	from script/rails:6:in `<main>'