Source map output path incorrect

[svenvandescheur]

I'm tryin to set this up to copy and minimize css files, seems to be working fairly straightforward but source mapping seems to be broken.

This is the copy configuration:

copy({
        targets: [
          {
            src: "src/**/*.css",
            dest: "dist",
            transform: createTransform({
              inline: true,
              minify: true,
              map: { inline: false },
            }),
          },
        ],
        flatten: false,
      }

This is my output config:

output: {
      dir: "dist",
      format: "esm",
      sourcemap: true,
      preserveModules: true,
    }

I'm copying nested css files and expect them to show up in the dist folder in a similar structure as the sources, but compiled. This closely resembles preserveModules (which doesn't seem to work with many rollup CSS solutions)

The processed files show up correctly, but the generated source map is written to the the project root (not even the dist/ directory). I'd expect them to be (able to be) next to the output file.

Is this possible using some sort of configuration?