Had some awesome fun with a compass sass –watch statement today. The problem that I ran into was related to image sprites.
A statement like this.
sass --watch --compass --sourcemap _css
Would get me this. And compass would quit on me.
NoMethodError: undefined method `parent' for nil:NilClass Use --trace for backtrace.
The problem, it turned out, was related to the name of the images that the sprite was building from. Compass does not like integers at the front of the images and will quit and not compile when it sees them.
Other people have seen this same error and it could be related to the image_dir name in the config file like here or here, but this is another problem that you might run into.
“You like integer named images in a compass sprite folder. Nil Class” – Russell from Fat Albert.