symfony/symfony-docs — pull request #1698 by greg0ire (2012-09-10 21:06:43+00:00)
Title: This is based on my experience

I was getting errors saying assetic.sass should be an array, then found this in my cache:
app/cache/dev/appDevDebugProjectContainer.xml
370: /usr/bin/sass
372: Assetic\Filter\Sass\SassFilter
373: /usr/bin/sass
374: null
375: null