Css modules don't work with ?inline in production build

[Marcisbee]

Describe the bug

I have a need to share css between iframe and parent. And the way I figure I would do this is use css modules + ?inline to get the parsed contents into <style> element in iframe.

This works only in dev mode, whenever I build it ?inline returns empty string.

npm run dev

Works as expected (color get shared):

---

npm run build && npm run preview

Doesn't work as expected (iframe gets no style):

Reproduction

https://stackblitz.com/edit/vitejs-vite-qgqdy8?file=main.js&terminal=dev

System Info

System:
    OS: macOS 12.0.1
    CPU: (8) arm64 Apple M1
    Memory: 78.77 MB / 16.00 GB
    Shell: 5.8 - /bin/zsh
  Binaries:
    Node: 16.13.0 - /var/folders/pd/qdphcr2548v8rbws7vjfjw180000gn/T/fnm_multishells/78075_1645101839115/bin/node
    Yarn: 1.22.17 - ~/.yarn/bin/yarn
    npm: 8.1.0 - /var/folders/pd/qdphcr2548v8rbws7vjfjw180000gn/T/fnm_multishells/78075_1645101839115/bin/npm
  Browsers:
    Brave Browser: 94.1.30.87
    Chrome: 98.0.4758.102
    Firefox: 97.0
    Safari: 15.1
  npmPackages:
    vite: ^2.8.0 => 2.8.2

Used Package Manager

npm

Logs

No response

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