You may come across the following error in your web deving if you ever use the Susy math library:
“>Undefined mixin ‘span-columns’.)"
Wondering how to fix this? If you’re opening a project that’s kicking out this error in Grunt or whatever task-manager you might be running, it means that your @import susy; is trying to call the most recent version of susy.
Simply change your whevever in your Sass you call
@import susy; to
Took me longer than I’d care to solve that.