`experimental.bundledDev` fails to resolve virtual modules (breaks UnoCSS and Vue DevTools)

[Wyatex]

Describe the bug

When enabling the experimental.bundledDev option in Vite, plugins that rely on injecting and serving Virtual Modules fail to work correctly.

I tested this with two major ecosystem plugins: unocss and vite-plugin-vue-devtools. Both broke simultaneously when bundledDev: true was enabled. It seems the dev server fails to resolve, bundle, or serve virtual modules, resulting in 404 errors or missing code.

Reproduction

https://github.com/Wyatex/bundledDevBug

Steps to reproduce

1. Scaffold a standard Vite + Vue project.
2. Install unocss and vite-plugin-vue-devtools, and add them to the plugins array.
3. Import virtual:uno.css in main.ts and use some utility classes.
4. Enable experimental.bundledDev in vite.config.ts:

   export default defineConfig({
     experimental: {
       bundledDev: true
     },
     plugins: [
       VueDevTools(),
       UnoCSS(),
       vue(),
     ]
   })

System Info

System:
    OS: Windows 11 10.0.26200
    CPU: (16) x64 AMD Ryzen 7 8845HS w/ Radeon 780M Graphics     
    Memory: 29.31 GB / 61.79 GB
  Binaries:
    Node: 26.4.0 - C:\Users\wyate\AppData\Local\fnm_multishells\54680_1783304385204\node.EXE
    npm: 11.17.0 - C:\Users\wyate\AppData\Local\fnm_multishells\54680_1783304385204\npm.CMD
    pnpm: 11.9.0 - C:\Users\wyate\AppData\Local\fnm_multishells\54680_1783304385204\pnpm.CMD
    bun: 1.3.7 - C:\Users\wyate\.bun\bin\bun.EXE
    Deno: 2.9.0 - C:\Users\wyate\.deno\bin\deno.EXE
  Browsers:
    Chrome: 147.0.7727.139
    Edge: Chromium (149.0.4022.98)
    Internet Explorer: 11.0.26100.8115
  npmPackages:
    @vitejs/plugin-vue: ^6.0.7 => 6.0.7 
    vite: ^8.1.3 => 8.1.3

Used Package Manager

pnpm

Logs

No response

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Make sure this is a Vite issue and not a framework-specific issue. For example, if it's a Vue SFC related bug, it should likely be reported to vuejs/core instead.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion or join our Discord Chat Server.
• The provided reproduction is a minimal reproducible example of the bug.

[sapphi-red]

related: vitejs/devtools#386

Currently, the transformIndexHtml hook in those plugins would have to add order: 'pre'. But we haven't decided whether that should be the way or if we can change the order: undefined behavior.

[Undefined100]

我也遇到了，开启bundledDev: true后，unocss的样式全部丢失了

[Undefined100]

I wanna what time this bug will be resolved？