Q: How to link scss file with style sheet link tag in Ruby on Rails <%= stylesheet_link_tag 'main', media: 'all', 'data-turbolinks-track' =>true  %>

Ruby on Rails seems to assume it's a main.css and throw an error. 
How do I link this correctly to main.scss?  

A: Only application.css.scss is precompiled by default. All files that are required through this file are also compiled. Normally, you would request your other files from within this file using either *= require_tree and *= require_self or @import.
If you still want to explicitly include the main.css.scss using stylesheet_link_tag like in your question, you need to add it to your list of precompiled assets in config/initializers/assets/ like so:
Rails.application.config.assets.precompile += %w( main.css )

