How come it can't generate sourcemaps for css?

[thany]

Trying to get it to output some kind of sourcemap (anything really at this point) for css. Nothing is working so far. I've set every concievable sourcemap flag to true. I wonder how many more flags it needs.

This is the config, stripped to relevant parts:

import { defineConfig } from 'vite';
import { resolve, extname } from 'path';

import { includePaths as normaliseIncludePaths } from 'node-normalize-scss';

export default defineConfig({
    build: {
        outDir: settings.output.build,
        emptyOutDir: false,
        rollupOptions: {
            input: {
                main: resolve(__dirname, settings.input.javascript),
                styles: resolve(__dirname, settings.input.sass),
            },
            output: {
                entryFileNames: 'javascript/[name].js',
                chunkFileNames: 'javascript/[name].js',
                assetFileNames: '[name][extname]',
            },
        },
        sourcemap: true,
        cssCodeSplit: false,
        minify: false,
    },
    css: {
        devSourcemap: true,
        preprocessorOptions: {
            scss: {
                sourceMap: true,
                sourceMapIncludeSources: true,
            },
        },
    },
});

You'd think one of those sourcemap flags would make it generate sourcemaps, right? Well, nothing. Nothing at all. Not even a file in the wrong location or with incorrect source paths. Just absolutely buggerall, I think is the technical term.

I also can't know what isn't generating the sourcemaps, and what should be generating sourcemaps. Is it sass-embedded? Is it Rollup? Is it Vite itself? No idea where neither the responsibility is, nor where the hiccup is happening.

Javascript sourcemaps work fine. They worked fine by just adding sourcemap: true and that was it. Why is it so difficult for Sass? And what should I add to make it work please?