Just so everyoine knows, we recently were using node-sass (a C++ node binder) which is now deprecated. Instead, we are now using sass (javascript). The sass version does better checking (linting) and therefore, if you have errors, these will show up.
One thing I have noticed though, is if you are missing the colon (:) completely, you get a warning and it keeps on trucking (instead of failing), but it gives you a message about no descripter so won’t be used. For the line number it gives you, look up 1 higher for the issue.