Regression in StaticSitesClient 20260720.247.2: Next.js hybrid deployments fail with "Failed to deploy the Azure Functions" (worked on 20260714.240.1)

[danadrianparaschiv]

Summary

Since the StaticSitesClient rolled from 20260714.240.1 to 20260720.247.2 (~2026-07-21 → 2026-07-27 in our deployments), every deployment of our Next.js hybrid app fails with:

Status: Failed. Time: 33.0460794(s)
Deployment Failed :(
Deployment Failure Reason: Failed to deploy the Azure Functions.

The failure is server-side, after a successful artifact upload ("Finished Upload. Polling on deployment." → Failed at ~33s), on two independent Static Web Apps resources (staging + production, separate subscriptions). The identical application code deployed successfully on 2026-07-21 with client 20260714.240.1.

Evidence it is not application-side

We reproduced the failure 5 times across every variable we control:

Attempt	App state	Result
2026-07-21	Next 16.2.6	✅ success (client 20260714.240.1)
2026-07-27 #1	Next 16.2.12	❌ (client 20260720.247.2)
2026-07-27 #2	Next 16.2.12, sharp/@img excluded via outputFileTracingExcludes (rules out bundle size)	❌
2026-07-27 #3	Reverted to Next 16.2.6 — near-identical to the last green deploy	❌
2026-07-27 #4	Next 16.2.6 + staticwebapp.config.json platform.apiRuntime: node:20	❌

The only delta between the last success and the failures is the deployment client version printed in the action logs.

Environment

• GitHub Actions, Azure/static-web-apps-deploy@v1, prebuilt app (skip_app_build: true), Next.js hybrid (App Router, ISR + server rendering), output .next
• Node warning in logs: "Defaulting to version: 22" (identical in the last successful run)
• Log excerpt (identical shape in all failures): Detected the following framework: Next.js → Repackaged Next.js app to deploy on the backend → Zipping Api Artifacts → upload OK → poll → Failed to deploy the Azure Functions

Ask

1. Was there a change in the Next.js repackaging / functions provisioning path in 20260720.247.2?
2. Is there a supported way to pin the deployment client version in the GitHub Action as a mitigation?

Deployment IDs available on request (e.g. 32541b25-d739-419a-8fcc-62ddaadeb7a3, 2026-07-27). Happy to provide full logs privately.