Duplicate metatags when using next/head in pages router #81655
Description
Link to the code that reproduces this issue
https://github.com/sommeeeer/next-head-duplicate-metatags
To Reproduce
pnpm build && pnpm start- Visit
http://localhost:3000/head - Inspect
<head>and see duplicate meta tags.
Current vs. Expected behavior
I expect it to work like on 15.3.x. Without duplicate meta tags in <head>.
Provide environment information
Operating System:
Platform: linux
Arch: x64
Version: #63-Ubuntu SMP PREEMPT_DYNAMIC Tue Apr 15 19:04:15 UTC 2025
Available memory (MB): 14800
Available CPU cores: 16
Binaries:
Node: 20.18.0
npm: 11.4.1
Yarn: N/A
pnpm: 9.6.0
Relevant Packages:
next: 15.4.2-canary.0 // Latest available version is detected (15.4.2-canary.0).
eslint-config-next: 15.4.1
react: 19.1.0
react-dom: 19.1.0
typescript: 5.8.3
Next.js Config:
output: N/AWhich area(s) are affected? (Select all that apply)
Pages Router
Which stage(s) are affected? (Select all that apply)
next start (local), next dev (local)
Additional context
I tested on latest canary 15.4.2-canary.0. Issue still persists there. Somewhere in the render process the head tags get duplicated.