See this blog post: http://sass.logdown.com/posts/7081811

And this issue over at sass-rails: rails/sass-rails#420

The ruby implementation of sass is already designated as "deprecated", so it's already in maintenance mode. They will be archiving the repo and not accepting issues or pull requests after March 29 2019. So it is going to eventually get stale.

I would like to suggest this gem switch to sassc-rails or sassc, which uses the new C implementation of Sass.