# X_DEPLOY_BUILD_UNSTAMPED

## Means

the deployment answers with no build header

## Typical cause

/readyz answered 2xx with no x-ultimate-build, so no sample can name a build

## Fix

`x build --target docker --json` — stamps BUILD_ID into the image; or set BUILD_ID in the image's environment

[CLI and verify](/error-codes#cli-and-verify)