[Bug]: Build hangs on error when setting api: "modern-compiler" in sass-loader

[Thiry1]

System Info

System:
OS: macOS 14.7
CPU: (8) arm64 Apple M2
Memory: 90.69 MB / 24.00 GB
Shell: 3.2.57 - /bin/bash
Binaries:
Node: 22.14.0 - ~/.nodebrew/current/bin/node
Yarn: 1.22.22 - /opt/homebrew/bin/yarn
npm: 10.9.2 - ~/.nodebrew/current/bin/npm
pnpm: 8.15.3 - ~/.nodebrew/current/bin/pnpm
Browsers:
Chrome: 134.0.6998.89
Chrome Canary: 136.0.7072.0
Edge: 134.0.3124.68
Safari: 18.0
npmPackages:
@rspack/cli: ^1.2.8 => 1.2.8
@rspack/core: ^1.2.8 => 1.2.8

Details

Build hangs on error when setting api: "modern-compiler" in sass-loader.
In webpack, the process exits when an error occurs.
Removing the following setting allows the process to exit in rspack as well:

{
  loader: "sass-loader",
  options: {
-    api: "modern-compiler",
     implementation: require("sass-embedded"),
  }
}

Reproduce link

https://github.com/Thiry1/rspack-bug-repro/compare/hang-sass-loader

Reproduce Steps

1. clone repro repo
2. git switch hang-sass-loader
3. npm i
4. npm run build:rspack

[Thiry1]

I suspect that the issue is caused by the shutdown hook not being called on build errors, preventing sass-embedded from being disposed of.

I have confirmed that when Sass builds successfully, this hook is called and sass-embedded is properly disposed of.
https://github.com/webpack-contrib/sass-loader/blob/300ac87f3cd04183fd0d6ec9b931d52764d8ca64/src/utils.js#L775-L777

[Thiry1]

According to the following comment, it seems that close is intentionally not called in case of an error. However, as a result, the shutdown hook is not triggered, and sass-embedded is not disposed of.

rspack/packages/rspack-cli/src/commands/build.ts

Lines 124 to 129 in fef9234

	(error: Error | null, stats: Stats | MultiStats | undefined) => {
	// If there is a compilation error, the close method should not be called,
	// Otherwise Rspack may generate invalid caches.
	if (error || stats?.hasErrors()) {
	errorHandler(error, stats);
	} else {