Uncaught error on startup: Cannot read env of undefined

[HalfdanJ]

Describe the bug

After updating sveltekit from 2.6.2 to 2.6.3, the build version of the app is broken on startup with the following error

public.Dvbes-1E.js:1 Uncaught (in promise) TypeError: Cannot read properties of undefined (reading 'env')
    at public.Dvbes-1E.js:1:376

The code that is running is

const d = globalThis.__sveltekit_1n0gls.env;

I can see that globalThis.__sveltekit_1n0gls doesn't exist, but globalThis.__sveltekit_aqr0w does. So it seems like somehow the keys gets mixed up in the build. I suspect introduced in #12700

Reproduction

1. Create a new sveltekit project, and make a build
2. Take note of the variable name globalThis.__sveltekit_* in client/_app/immutable/chunks/entry.*.js
3. Make a change to package.json, for example add a new dependency
4. Make new build, notice that the entry.*.js file has not changed filename (same key), but that globalThis.__sveltekit_* has changed key, so the file has become mutable

The build is still valid by itself, but if application is served behind a cdn, the old file will be served since filename doesnt change.

Logs

No response

System Info

System:
    OS: macOS 14.6.1
    CPU: (12) arm64 Apple M2 Max
    Memory: 2.38 GB / 64.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 20.15.1 - ~/.nvm/versions/node/v20.15.1/bin/node
    npm: 10.7.0 - ~/.nvm/versions/node/v20.15.1/bin/npm
    pnpm: 9.1.1 - ~/.nvm/versions/node/v20.15.1/bin/pnpm
    bun: 1.1.5 - ~/.bun/bin/bun
  Browsers:
    Chrome: 129.0.6668.90
    Safari: 17.6
  npmPackages:
    @sveltejs/adapter-node: 5.2.5 => 5.2.5 
    @sveltejs/enhanced-img: 0.3.8 => 0.3.8 
    @sveltejs/kit: 2.6.3 => 2.6.3 
    svelte: 4.2.19 => 4.2.19 
    vite: 5.4.8 => 5.4.8

Severity

blocking an upgrade

Additional Information

No response

[HalfdanJ]

After further looking into this, it seems like this might be a cache / cdn issue. The file public.Dvbes-1E.js is served with the wrong key 1n0gls, but when i look at the docker artifact that has been deployed, the files contains the right key 1lw3djs. Is it possible the change in #12700 resulted in the key changing, but the filename staying the same, and therefore resulting in the file having changed content without changing filename?

[HalfdanJ]

I have isolated the issue and updated the issue to contain reproduction steps. Issue is that the key changes when package.json changes, but the filename doesnt change so it has become mutable.

[sickl8]

Encountered the same problem recently, fixed by enabling "Disable Cache" in browser dev tools for each CI build of a commit