Build fails using adapter-vercel

Describe the bug

I am working on updating one of my apps (from 367). Finally got it all working in pnpm dev, so I go to build and… fail. I have been racking my brain but unfortunately I haven’t been able to pin down exactly why. It seems that it is something with the adapter itself, but obviously not all adapter-vercel builds are failing, so maybe it is something on my end. Ahh! 😕 Maybe this has been seen before and there is a known solution? 🤞🏻

The vite part of the build works fine, so pnpm preview works, just not the final build. I have also tried building with adapter-node which worked as expected and even adapter-netlify which worked, although I did not deploy it.

Reproduction

Sorry, no repro. I have not been able to pin down exactly what is causing this. Feel free to close I guess but just frustrating since I deploy to vercel. I would just say it is obviously something on my end, but it is weird that adapter-node and adapter-netlify build successfully if that is the case.

Logs

error during build:
TypeError: object null is not iterable (cannot read property Symbol(Symbol.iterator))
    at file:///Users/caleb/repos/[redacted]/node_modules/.pnpm/@sveltejs+adapter-vercel@1.0.0-next.78/node_modules/@sveltejs/adapter-vercel/index.js:318:33
    at Set.forEach (<anonymous>)
    at create_function_bundle (file:///Users/caleb/repos/[redacted]/node_modules/.pnpm/@sveltejs+adapter-vercel@1.0.0-next.78/node_modules/@sveltejs/adapter-vercel/index.js:307:18)
    at async generate_serverless_function (file:///Users/caleb/repos/[redacted]/node_modules/.pnpm/@sveltejs+adapter-vercel@1.0.0-next.78/node_modules/@sveltejs/adapter-vercel/index.js:153:5)
    at async adapt (file:///Users/caleb/repos/[redacted]/node_modules/.pnpm/@sveltejs+adapter-vercel@1.0.0-next.78/node_modules/@sveltejs/adapter-vercel/index.js:235:5)
    at async adapt (file:///Users/caleb/repos/[redacted]/node_modules/.pnpm/@sveltejs+kit@1.0.0-next.514_svelte@3.51.0+vite@3.1.7/node_modules/@sveltejs/kit/src/core/adapt/index.js:28:2)
    at async Object.handler (file:///Users/caleb/repos/[redacted]/node_modules/.pnpm/@sveltejs+kit@1.0.0-next.514_svelte@3.51.0+vite@3.1.7/node_modules/@sveltejs/kit/src/exports/vite/index.js:488:6)
    at async PluginDriver.hookParallel (file:///Users/caleb/repos/[redacted]/node_modules/.pnpm/rollup@2.78.1/node_modules/rollup/dist/es/shared/rollup.js:22632:17)
    at async Object.close (file:///Users/caleb/repos/[redacted]/node_modules/.pnpm/rollup@2.78.1/node_modules/rollup/dist/es/shared/rollup.js:23709:13)
    at async Promise.all (index 0)
ERROR Command failed with exit code 1.

System Info

System:
    OS: macOS 12.6
    CPU: (10) arm64 Apple M1 Max
    Memory: 1.45 GB / 32.00 GB
    Shell: 5.8.1 - /bin/zsh
  Binaries:
    Node: 16.17.0 - ~/.nodenv/versions/16.17.0/bin/node
    Yarn: 1.22.15 - ~/.nodenv/shims/yarn
    npm: 8.15.0 - ~/.nodenv/versions/16.17.0/bin/npm
  Browsers:
    Chrome: 106.0.5249.119
    Firefox: 105.0.3
    Safari: 16.0
  npmPackages:
    @sveltejs/adapter-netlify: ^1.0.0-next.80 => 1.0.0-next.80 
    @sveltejs/adapter-node: ^1.0.0-next.97 => 1.0.0-next.97 
    @sveltejs/adapter-vercel: ^1.0.0-next.78 => 1.0.0-next.78 
    @sveltejs/kit: ^1.0.0-next.514 => 1.0.0-next.514 
    svelte: ^3.51.0 => 3.51.0 
    vite: ^3.1.7 => 3.1.7

Severity

blocking all usage of SvelteKit

Additional Information

No response

[dummdidumm]

I created https://github.com/vercel/nft/issues/315 first because I think that’s the source of this issue

[dummdidumm]

Yes, we left that in as a warning to notify people that something may not work - but if it does you can ignore it. It’s a warning, not an error, so the build succeeds.