10 days ago
My backend deployment is failing due to an internal builder error that's not caused by my code. Build Failed: build daemon returned an error: "secret ID missing for "" environment variable"
Details:
Service ID: 7b3eaca0-305c-40cc-af13-ec489004009a
Deployment ID: f0512375-5923-414c-ab81-5d4d2916e11a
Project: welcoming-vibrancy
Builder image: ghcr.io/railwayapp/railpack-builder:mise-2026.8.3
Key findings:
The same commit deployed successfully with the previous builder image (mise-2026.7.15) — no code changes, just a builder upgrade
The triggering commit only modified Next.js/Vercel frontend files (no backend changes)
Python version resolved correctly (3.12.13) and requirements.txt is untouched
The error happens identically in two consecutive deployments of the same commit
This is a buildkit secret-mounting issue in the builder, not an application problem
This appears to be a regression in the latest mise builder image. Can anyone from the Railway team investigate?
1 Replies
10 days ago
Your service has an environment variable named NEXT_PUBLIC_APP_URL with a leading space in the name. The updated builder image is stricter about secret ID validation during BuildKit secret mounting, and that whitespace-prefixed name produces an empty secret ID, which is the "secret ID missing" error you're seeing. Remove the leading space so the variable is named NEXT_PUBLIC_APP_URL and redeploy.
Status changed to Awaiting User Response Railway • 10 days ago
Status changed to Solved nezkaa • 9 days ago