manual i18n routing not working with prerendered 404 page

[stefanprobst]

Astro Info

Astro                    v4.6.1
Node                     v20.12.2
System                   Linux (x64)
Package Manager          pnpm
Output                   hybrid
Adapter                  @astrojs/node
Integrations             none

If this issue only occurs in one browser, which browser is a problem?

No response

Describe the Bug

with the recently added manual i18n routing strategy, and this middlwware, i want to redirect the "/" root route to the default locale "/en".

in a production build, when the src/pages/404.astro file has export const prerender = false, i get the expected 307 redirect. however, when 404.astro has export const prerender = true i get a 404.

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to reproduce:

1. git clone git@github.com:stefanprobst/issue-astro-i18n-manual.git && cd issue-astro-i18n-manual && pnpm install
2. pnpm run build
3. pnpm run preview
4. curl -i http://localhost:3000 which prints: "HTTP/1.1 404 Not Found"

now, change the prerender mode in 404.astro to false:

1. sed -i "s/prerender = true/prerender = false/" src/pages/404.astro
2. pnpm run build
3. pnpm run preview
4. curl -i http://localhost:3000 which prints: "HTTP/1.1 307 Temporary Redirect"

What's the expected result?

root route "/" should be redirected to default locale "/en" when 404.astro has export const prerender = true (or with output: "hybrid").

Link to Minimal Reproducible Example

https://github.com/stefanprobst/issue-astro-i18n-manual

Participation

• I am willing to submit a pull request for this issue.