ReferenceError: __VUE_PROD_DEVTOOLS__ is not defined when using vue-i18n in SSR / externalized node_modules

[YKDZ]

Reporting a bug?

If vue-i18n is externalized in a Vite SSR build, importing its distributed bundle at runtime causes the server to throw the following error:

PS C:\Users\YKDZ\Desktop\my-app> pnpm preview

> @ preview C:\Users\YKDZ\Desktop\my-app
> cross-env NODE_ENV=production node dist/server/index.js

Server running at http://localhost:3000
file:///C:/Users/YKDZ/Desktop/my-app/node_modules/.pnpm/vue-i18n@11.1.11_vue@3.5.21_typescript@5.9.2_/node_modules/vue-i18n/dist/vue-i18n.mjs:2064
            if (((process.env.NODE_ENV !== 'production') || __VUE_PROD_DEVTOOLS__) && !false) {
                                                            ^

ReferenceError: __VUE_PROD_DEVTOOLS__ is not defined
    at Object.install (file:///C:/Users/YKDZ/Desktop/my-app/node_modules/.pnpm/vue-i18n@11.1.11_vue@3.5.21_typescript@5.9.2_/node_modules/vue-i18n/dist/vue-i18n.mjs:2064:61)
    at Object.use (C:\Users\YKDZ\Desktop\my-app\node_modules\.pnpm\@vue+runtime-core@3.5.21\node_modules\@vue\runtime-core\dist\runtime-core.cjs.prod.js:2995:18)
    at onCreateApp (file:///C:/Users/YKDZ/Desktop/my-app/dist/server/entries/pages_index.mjs:43:12)
    at file:///C:/Users/YKDZ/Desktop/my-app/node_modules/.pnpm/vike-vue@0.9.2_vike@0.4.238_fa18f387c1acb616273f321ab9e11cd4/node_modules/vike-vue/dist/getHeadSetting-CluLhiHU.js:18:14
    at Array.map (<anonymous>)
    at callCumulativeHooks (file:///C:/Users/YKDZ/Desktop/my-app/node_modules/.pnpm/vike-vue@0.9.2_vike@0.4.238_fa18f387c1acb616273f321ab9e11cd4/node_modules/vike-vue/dist/getHeadSetting-CluLhiHU.js:15:33)
    at createVueApp (file:///C:/Users/YKDZ/Desktop/my-app/node_modules/.pnpm/vike-vue@0.9.2_vike@0.4.238_fa18f387c1acb616273f321ab9e11cd4/node_modules/vike-vue/dist/getHeadSetting-CluLhiHU.js:74:9)
    at renderPageToHtml (file:///C:/Users/YKDZ/Desktop/my-app/node_modules/.pnpm/vike-vue@0.9.2_vike@0.4.238_fa18f387c1acb616273f321ab9e11cd4/node_modules/vike-vue/dist/integration/onRenderHtml.js:74:33)
    at Object.onRenderHtml [as hookFn] (file:///C:/Users/YKDZ/Desktop/my-app/node_modules/.pnpm/vike-vue@0.9.2_vike@0.4.238_fa18f387c1acb616273f321ab9e11cd4/node_modules/vike-vue/dist/integration/onRenderHtml.js:27:38)
    at file:///C:/Users/YKDZ/Desktop/my-app/node_modules/.pnpm/vike@0.4.238_vite@7.1.4_@types+node@20.19.11_tsx@4.20.5_/node_modules/vike/dist/esm/shared/hooks/execHook.js:37:65

Node.js v22.17.1
 ELIFECYCLE  Command failed with exit code 1.

This issue can be easily fixed by setting vue-i18n to noExternal.

Expected behavior

vue-i18n should work correctly when externalized.

Reproduction

https://github.com/YKDZ/vue-i18n-ssr-external-issue-reproduction

System Info

System:
    OS: Windows 11 10.0.26100
    CPU: (16) x64 Intel(R) Core(TM) i7-10700K CPU @ 3.80GHz
    Memory: 6.64 GB / 31.83 GB
  Binaries:
    Node: 22.17.1 - ~\AppData\Local\fnm_multishells\42492_1756824206758\node.EXE
    npm: 10.9.2 - ~\AppData\Local\fnm_multishells\42492_1756824206758\npm.CMD
    pnpm: 10.15.0 - ~\AppData\Local\fnm_multishells\42492_1756824206758\pnpm.CMD
  Browsers:
    Edge: Chromium (139.0.3405.125)
    Internet Explorer: 11.0.26100.1882
  npmPackages:
    @vitejs/plugin-vue: ^6.0.1 => 6.0.1
    @vue/compiler-sfc: ^3.5.19 => 3.5.21
    @vue/server-renderer: ^3.5.19 => 3.5.21
    vite: ^7.1.3 => 7.1.4
    vue: ^3.5.19 => 3.5.21
    vue-eslint-parser: ^10.2.0 => 10.2.0
    vue-i18n: ^11.1.11 => 11.1.11

Screenshot

No response

Additional context

No response

Validations

• Read the Contributing Guidelines
• Read the Documentation
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Check that this is a concrete bug. For Q&A open a GitHub Discussions

[kazupon]

Hi!
Thank you for reporting!

When vue-i18n need SSR build, we can support for it with @intlify/unplugin-vue-i18n and ssr option.
https://github.com/intlify/bundle-tools/tree/main/packages/unplugin-vue-i18n#ssr

But, I have realized vue-i18n docs is poor about it.
About SSR configuration, Optimization chapter should be written it.
https://vue-i18n.intlify.dev/guide/advanced/optimization.html#optimization

[kazupon]

@YKDZ
If you have still issue, please let ask to us.
3 days after, we will close this issue.