I don't think Jekyll (yet) supports the original SASS cards.
For my projects, I added the SASS build step for my deployment script that generates the source map:
#!/bin/bash
DEST="./_site/style"
ORIGINALS=$DEST/originals
INCLUDES=$ORIGINALS/_sass
rm $ORIGINALS -r
mkdir $ORIGINALS
cp ./_sass/ $ORIGINALS -r
SASS_FILE=style
tail -n +3 ./style/$SASS_FILE.scss > $ORIGINALS/$SASS_FILE.scss
sass --load-path $INCLUDES --sourcemap=auto $ORIGINALS/$SASS_FILE.scss $DEST/$SASS_FILE.css
Attention!
Do not forget to configure your web server on server types of SCSS server.
Additional notes
The important thing is that the SCSS source files are also deployed to the web server so that the browser can access them!
sourcemap auto, SCSS.