Rspack build time is higher than webpack

[Forceres]

Current Behavior

Currently my microservice build time with rspack is 25% higher than webpack. I don't exactly know why or what nx does under the hood.

Expected Behavior

Each benchmark tells that rspack is way faster, so it is expected to have smaller build time.

GitHub Repo

.

Steps to Reproduce

1. Have some unbuildable libs with project references.
2. Create NestJS application and use libs there.
3. Try to build with rspack and webpack, measure the build time.

Nx Report

NX   Report complete - copy this into the issue template

Node           : 22.18.0
OS             : linux-x64
Native Target  : x86_64-linux
bun            : 1.3.3

nx                     : 22.1.0
@nx/js                 : 22.1.0
@nx/jest               : 22.1.0
@nx/linter             : 16.0.0-beta.1
@nx/eslint             : 22.1.0
@nx/workspace          : 22.1.0
@nx/cypress            : 22.1.0
@nx/devkit             : 22.1.0
@nx/eslint-plugin      : 22.1.0
@nx/module-federation  : 22.1.0
@nx/nest               : 22.1.0
@nx/next               : 22.1.0
@nx/node               : 22.1.0
@nx/playwright         : 22.1.0
@nx/plugin             : 22.1.0
@nx/react              : 22.1.0
@nx/rollup             : 22.1.0
@nx/rspack             : 22.1.0
@nx/rsbuild            : 22.1.0
@nx/storybook          : 22.1.0
@nx/vite               : 22.1.0
@nx/vitest             : 22.1.0
@nx/vue                : 22.1.0
@nx/web                : 22.1.0
@nx/webpack            : 22.1.0
@nx/docker             : 22.1.0
typescript             : 5.9.3
---------------------------------------
Registered Plugins:
@nx/js/typescript
@nx/eslint/plugin
@clickascend-integrations/biome
@nx/jest/plugin
@nx/vite/plugin
@nx/rsbuild
@nx/rspack/plugin
---------------------------------------
Community plugins:
@nx/nx-plugin : 16.0.0-beta.1
---------------------------------------
Cache Usage: 1.76 MB / 95.19 GB
---------------------------------------
The following packages should match the installed version of nx
  - @nx/linter@16.0.0-beta.1

To fix this, run `nx migrate nx@22.1.0`

Failure Logs

Package Manager Version

bun@1.3.3

Operating System

• macOS
• Linux
• Windows
• Other (Please specify)

Additional Information

No response