@vitejs/plugin-legacy warning Top-level await is not available when renderModernChunks is false

[wherewhere]

Describe the bug

When I build a project with @vitejs/plugin-legacy by set

legacy({
    targets: "Edge >= 18",
    polyfills: true,
    renderModernChunks: false
})

It warning [TOLERATED_TRANSFORM] Top-level await is not available in the configured target environment.

It should not warning since renderModernChunks is false so it will not have any effect. And if I set modernTargets: "defaults", it not warning Top-level await is not available but warning plugin-legacy 'modernTargets' option overrode the builtin targets of modern chunks. Some versions of browsers between legacy and modern may not be supported.

Reproduction

https://github.com/wherewhere/VueForUWP

Steps to reproduce

• Create a vite project with @vitejs/plugin-legacy
• Set targets: "Edge >= 18"
• Write some top await
• Build it

System Info

System:
  OS: Windows 11 10.0.26200
  CPU: (8) x64 Intel(R) Core(TM) Ultra 7 266V
  Memory: 2.00 GB / 15.72 GB
Binaries:
  Node: 26.1.0 - C:\Program Files\nodejs\node.EXE
  Yarn: 1.22.22 - C:\Users\qq251\AppData\Roaming\npm\yarn.CMD
  npm: 11.13.0 - C:\Program Files\nodejs\npm.CMD
  bun: 1.3.10 - C:\Users\qq251\AppData\Roaming\npm\bun.CMD
npmPackages:
  @vitejs/plugin-legacy: ^8.0.0 => 8.0.2 
  @vitejs/plugin-vue: ^6.0.0 => 6.0.7 
  vite: ^8.0.0 => 8.0.14

Used Package Manager

npm

Logs

Click to expand!

> vue-uwp@0.0.1 build
> vite build

vite v8.0.14 building client environment for production...
✓ 89 modules transformed.
computing gzip size...
dist/index.html                                             0.81 kB │ gzip:  0.43 kB
dist/assets/Symbols-Cnx9HBaY.ttf                           47.48 kB
dist/assets/base.min-DFyWONOv.js                          331.39 kB
dist/assets/ui.min-Cg9LWWJn.js                            872.11 kB
dist/assets/WinJSControl-legacy-Cwrq1Znq.js                 0.70 kB │ gzip:  0.48 kB │ map:   3.30 kB
dist/assets/NotFoundView-legacy-Bz9bLDXs.js                 1.87 kB │ gzip:  1.18 kB │ map:   4.65 kB
dist/assets/IndexView-legacy-Dl3G5J8V.js                    7.12 kB │ gzip:  2.01 kB │ map:  19.23 kB
dist/assets/theme-legacy-CVnodPOl.js                       11.04 kB │ gzip:  4.92 kB │ map:  79.74 kB
dist/assets/package-legacy-DT7ZUDks.js                     17.31 kB │ gzip:  6.64 kB │ map:  58.11 kB
dist/assets/vue-router-legacy-3HN-QJuv.js                  25.25 kB │ gzip:  9.69 kB │ map: 146.60 kB
dist/assets/SettingsView-legacy-BhVMz_yx.js                45.87 kB │ gzip: 11.19 kB │ map: 103.63 kB
dist/assets/_plugin-vue_export-helper-legacy-BmFU7m2N.js   59.28 kB │ gzip: 23.54 kB │ map: 442.15 kB
dist/assets/polyfills-legacy-Ds68o5DC.js                  108.22 kB │ gzip: 39.52 kB │ map: 500.85 kB
dist/assets/index-legacy-wFQTuR2H.js                      296.89 kB │ gzip: 31.96 kB │ map:  52.72 kB

[TOLERATED_TRANSFORM] Top-level await is not available in the configured target environment.
    ╭─[ index.ts:18:1 ]
    │
 18 │ await useScriptAsync(head, { src: baseJsUrl });
    │ ───────────────────────┬──────────────────────  
    │                        ╰──────────────────────── 
────╯

[TOLERATED_TRANSFORM] Top-level await is not available in the configured target environment.
    ╭─[ index.ts:20:1 ]
    │
 20 │ await useScriptAsync(head, { src: uiJsUrl });
    │ ──────────────────────┬─────────────────────  
    │                       ╰─────────────────────── 
────╯

✓ built in 7.77s

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]

The reproduction is not minimal and does not reproduce the warning.