astro:env showing undefined vars in production mode

[daspete]

Astro Info

Astro                    v5.1.7
Node                     v22.13.0
System                   Linux (x64)
Package Manager          npm
Output                   server
Adapter                  @astrojs/node
Integrations             astro-icon
                         @astrojs/tailwind
                         @astrojs/vue

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

No response

Describe the Bug

i defined a schema for some environment variables in the astro.config.mjs file.
When i run the project in dev mode, the import from the astro:env package works, for example like this:

import { API_URL } from 'astro:env/client'

But when i run the build and then start with

node ./dist/server/entry.mjs

the API_URL get's undefined, even there is the variable set in process.env

In the stackblitz example, you can just run:

npm run build
npm run start

to see the result.

What's the expected result?

The variables set with astro:env should not be undefined on production runtime.

Link to Minimal Reproducible Example

https://stackblitz.com/edit/github-f34drayg?file=src%2Fpages%2Findex.astro

Participation

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