404 Error when deploying to Vercel

[HeritagePalms]

Describe the bug

With the new API changes that were done (#3133), the new output folder is '.output' instead of '.vercel_build_output' and Vercel doesn't seem to know what to do with that.

I have the preset set to Sveltekit and had to do a manual override on the output folder to '.vercel_build_output' for it to work. Now, I followed the Vercel guide for the file system api (https://vercel.com/docs/file-system-api), and my deployments just go to a 404 page. I also added the manual output override to '.output' but the deployments fail if I do that.

I understand that this might be a Vercel thing instead of SvelteKit. If so, then let me know and I will head over there.

Thanks.

Reproduction

I don't have a public repo available, sorry.

Logs

No response

System Info

System:
    OS: macOS 12.1
    CPU: (8) x64 Intel(R) Core(TM) i7-4770HQ CPU @ 2.20GHz
    Memory: 100.13 MB / 16.00 GB
    Shell: 5.8 - /bin/zsh
  Binaries:
    Node: 14.17.0 - /usr/local/bin/node
    npm: 7.17.0 - /usr/local/bin/npm
  Browsers:
    Chrome: 96.0.4664.110
    Edge: 96.0.1054.62
    Firefox Developer Edition: 96.0
    Safari: 15.2
  npmPackages:
    @sveltejs/adapter-vercel: next => 1.0.0-next.33 
    @sveltejs/kit: ^1.0.0-next.114 => 1.0.0-next.208 
    svelte: ^3.34.0 => 3.44.3

Severity

blocking an upgrade

Additional Information

No response

[Rich-Harris]

same issue as #3143, closing (even though this was first :)

[Rich-Harris]

actually this might not be a dupe, reopening

[HeritagePalms]

I don't know if this helps but overriding the output folder in Vercel deployment settings allows the build to complete but the root folder structure in Vercel is just a 'server' and 'static' folder & 'routes-manifest.json' file. So my guess is that it doesn't know where the app starts, hence the 404 page.

[Rich-Harris]

Can you try with @sveltejs/adapter-vercel@1.0.0-next.34?

[HeritagePalms]

@sveltejs/adapter-vercel@1.0.0-next.34

This indeed solve my problem. Thanks!

[hemanthvalsaraj]

This ain't working for me either. Am I missing something here?

package.json
{ "@sveltejs/adapter-vercel": "next", "@sveltejs/kit": "next", "svelte": "^3.44.0", "svelte-preprocess": "^4.10.1", }

Error Log on Vercel
`

Using @sveltejs/adapter-vercel
Cannot read property 'location' of undefined
at get_single_valued_header (file:///vercel/path0/node_modules/@sveltejs/kit/dist/chunks/url.js:8:23)
at visit (file:///vercel/path0/node_modules/@sveltejs/kit/dist/chunks/index5.js:436:22)
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
Error: Command "yarn run build" exited with 1
`