Fix Vercel XML Rendering for Hugo

Deployed a Hugo blog to Vercel, but the site only showed index.xml content.

The Problem

The deployment log was full of warnings, no errors:

18:17:06.313 Installing Hugo version 0.58.2
18:17:24.069 Building sites …
WARN 2025/12/16 10:17:24 found no layout file for "HTML" for "home"
WARN 2025/12/16 10:17:24 found no layout file for "HTML" for "section"
WARN 2025/12/16 10:17:24 found no layout file for "HTML" for "page"

Build stats showed:

  Pages            |  6
  Paginator pages  |  0
  Non-page files   |  0
  Static files     |  2
  Processed images |  0
  Aliases          |  0
  Sitemaps         |  1
  Cleaned          |  0

Total in 12 ms

Only 2 static files, and the build finished in 12 milliseconds with a bunch of missing layout warnings. It basically didn’t build properly, so the site only served the RSS feed.

Root Cause

The key line in the log:

18:17:06.313 Installing Hugo version 0.58.2

Vercel defaults to Hugo 0.58.2, while my local version was 0.152.2.

Solution

Specify the Hugo version explicitly in vercel.json at the project root¹:

{
  "build": {
    "env": {
      "HUGO_VERSION": "0.152.2"
    }
  }
}

After redeploying, the log will show the correct version and the pages will render normally.