Astro Info

Astro                    v5.0.0-beta.12
Node                     v18.20.3
System                   Linux (x64)
Package Manager          npm
Output                   static
Adapter                  none
Integrations             @astrojs/preact

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

No response

Describe the Bug

Using the Astro tutorial on the content collections branch.

If I set the slug in the frontmatter of post-1.md and post-2.md to identical values (post-A in the MRE), the second post disappears from the /blog index page.

What's the expected result?

Loud error from Astro complaining about identical slugs.

Link to Minimal Reproducible Example

https://stackblitz.com/edit/github-bew6ny4w?file=src%2Fblog%2Fpost-2.md

Participation

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