"resources" not defined

I’m trying to get an SCSS file processed into a CSS file. I’m trying to follow the form given on https://gohugo.io/hugo-pipes/introduction/ but end up with a function "resources" not defined error.

If I use .Resources.Get instead I get a can't evaluate field Get error instead.

How do I use resources/pipes?

This suggests that you need to update Hugo to a more recent version. What is the output of hugo version?

Hugo Static Site Generator v0.40.1 linux/amd64 BuildDate: 2018-04-25T17:16:11Z

Is there any way from the docs to see when a feature was introduced?

Here: https://gohugo.io/news/ All Versions are listed. Try to search for your topic.