output.distPath.root directory does not create a new subfolder under already existing folder.

[Stepykun]

I'm trying to migrate from webpack to rsbuild and stumbled upon a problem.
Lets say that folder web/assets already exists in a root directory of a project. When I'm starting a server, the files are not generated under web/assets folder. But if, lets say, if I change web/assets, to a web_foo/assets (which does not exist in the project), the subfolder assets is created and I see all generated files.
Any ideas on how to make rsbuild create a subfolder for already existing folder?

import {defineConfig} from '@rsbuild/core';
import {pluginVue} from '@rsbuild/plugin-vue';

export default defineConfig({
  plugins: [pluginVue()],
  source: {
    alias: {
      root: './',
      //...lots of other aliases
    },
    entry: {
      app: './web/vwm/js/app.js',
      chosen: './web/vwm/js/chosen.js',
      jquery: './web/vwm/js/jquery-webpack.js',
     //...lots of other entries
    }
  },
  dev: {
    writeToDisk: true,
  },
  output: {
    cleanDistPath: true,
    manifest: true,
    distPath: {
      root: 'web/assets',
    },
  },
});