# X_JOB_CONCURRENCY_UNENFORCEABLE

## Means

`job.concurrency` is declared and cannot be enforced

## Typical cause

a jobs driver with no lease store — the cap then holds per **process** and the fleet runs `concurrency × replicas`. `job.concurrency` was documented, in the manifest, and enforced by nothing; the worker now refuses to start rather than run with the wrong number, which is what axiom 3 means by a convention that is not a build error not existing

## Fix

remove `concurrency` from the job `cause` names, or drop the `jobs:` field from `apps/<app>/runtime.ts` so the boot installs `postgresJobDriver()` over `DATABASE_URL` — the pg driver is the one with a lease store

[Jobs](/error-codes#jobs)