I've installed carbon-addon-xyz and added its index.scss file and now get:
File to import not found or unreadable: carbon-components/scss/globals/scss/colors.
in ......... node_modules\carbon-addons-cloud\scss\components\Card\_card.scss (line 1,
column 1)node-sass has multiple configuration options, one of them being includePaths. If you add node_modules to the includePaths configuration option, then you'll fix this issue.