If you run across this error when compiling zurb_foundation, I have a potential solution. At least, it worked for me.
I was using Ruby 1.9.2 with zurb_foundation 3.0.5. When I upgraded ruby to 1.9.3, I did not migrate the gems. I don’t remember how I installed zurb again. But when I ran “compass compile”, I got this error – for each sass file.
I did a “bundle install” and noticed that I was now using zurb_foundation 3.1.1. That is what was causing the issue.
I did a “gem uninstall zurb_foundation”, removed 3.1.1, then did a “compass compile” and every thing worked just fine.
So the solution is to use the previous version of the zurb gem that was working.