System Info

System:
OS: macOS 15.3.2
CPU: (16) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
Memory: 397.73 MB / 32.00 GB
Shell: 3.7.1 - /usr/local/bin/fish
Binaries:
Node: 22.14.0 - ~/.local/state/fnm_multishells/83719_1744138676757/bin/node
Yarn: 1.22.22 - ~/.local/share/yvm_fish/1.22.22/bin/yarn
npm: 11.1.0 - ~/.local/state/fnm_multishells/83719_1744138676757/bin/npm
Browsers:
Brave Browser: 116.1.57.62
Chrome: 135.0.7049.42
Chrome Canary: 137.0.7115.0
Edge: 135.0.3179.54
Safari: 18.3.1

Details

We have multiple teams migrating from webpack to rsbuild. When bumping rsbuild 1.2.6 -> 1.2.7 - a patch that bumped rspack 1.2.2 -> 1.2.3, webpack-license-plugin began outputting an empty licenses json file. I reported the issue in rsbuild and your team suggested to open an issue here instead (see here). This is the report to the plugin owner, he's not testing rspack but wouldn't mind accepting contributions.

If you could even help pinpoint the issue and/or suggest a way to salvage this plugin, that would be of great help to us.
Alternatively, if there's an easy way to achieve the same license summary file using your current tooling, a simple rspack/build plugin or if you have plans to add this as a config or builtin plugin - that would be great to know.

Thanks

Reproduce link

https://github.com/adguy360/rspack-license-plugin-test

Reproduce Steps

1. run npm start
2. go to http://localhost:3000/rsbuild-dev-server (should open automatically)
3. confirm licenses.json is an empty array
4. if you stop, run npm i @rsbuild/core@1.2.6 and rerun - you'll see licenses.json now shows data.

According to the changelog rsbuild@1.2.7 only bumped rspack to v1.2.3.