v5 beta - @astrojs/sitemap excluded from final static output with Vercel adapter

[dotnize]

Astro Info

Astro                    v5.0.0-beta.8
Node                     v22.11.0
System                   Linux (x64)
Package Manager          pnpm
Output                   static
Adapter                  @astrojs/vercel
Integrations             @astrojs/mdx
                         @astrojs/sitemap

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

No response

Describe the Bug

• https://github.com/withastro/astro/issues/12437

"@astrojs/sitemap": "^3.2.1",
"@astrojs/vercel": "^8.0.0-beta.4",
"astro": "^5.0.0-beta.8",

output is static

Using the versions above, the sitemap-index.xml and sitemap-0.xml files are created in /dist instead of .vercel/output/static, excluding them from the final vercel deployment.

What's the expected result?

astro-v4 branch in the repro

"@astrojs/sitemap": "^3.2.1",
"@astrojs/vercel": "^7.8.2",
"astro": "^4.16.13",

output is hybrid

No /dist folder is created at all after building, and the sitemap is properly generated in .vercel/output/static.

[build] Rearranging server assets...
[@astrojs/sitemap] `sitemap-index.xml` created at `.vercel/output/static`

Link to Minimal Reproducible Example

https://github.com/dotnize/astro-sitemap-vercel-static

Participation

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