---
id: "bug-1788"
status: "fixed"
status_updated: "2026-09-24"
status_note: ""
component: "lib"
severity: "unknown"
timestamp: "2026-09-07T10:00:00Z"
last_seen: "2026-09-19T09:00:00Z"
occurrences: 1
files: ["src/lib/xcelimit.c (instantiate_limit)"]
tags: ["scheduler", "limit-plugin", "kvmgr", "error-code-convention", "not-found-vs-error", "truthiness-bug", "gitea-46", "live-verified"]
related: ["bug-1495", "bug-1784", "bug-1785", "bug-1786", "bug-1787", "bug-1789"]
legacy: true
gitea_issue: 46
gitea_synced_status: "fixed"
---

# bug-1788: Found immediately after bug-1787: with the resmgr type-confusion fixed, instantiate_limit() still…

## Description
Found immediately after bug-1787: with the resmgr type-confusion fixed, instantiate_limit() still returned rc=-2/-ENOENT, still aborting limit_job_election()'s loop after the first limit -- reproduced identically on a scheduler's FIRST-EVER join to a freshly-started controller, ruling out any rejoin/resync-specific explanation.

## Environment
_Not recorded (migrated from buglog.json)._

## Reproduction
_Not recorded (migrated from buglog.json)._

## Root cause
The EXACT same defect class as bug-1786, recurring twice more, plus a related truthiness bug, all inside instantiate_limit() itself: (1) `rc = key_find(resmgr, vresname, &(vres->vres)); if (rc < 0) { return rc; } if (rc == 0) { add_vres(...); }` -- live-confirmed via targeted diagnostic instrumentation that this key_find's own "not found" signal is rc=-2/-ENOENT (not 0) for THIS resmgr-backed lookup too, so the `if (rc<0) return rc;` guard caught every first-ever vresname lookup before the add_vres()-creates-it branch could run. (2) The immediately following lookup of the limit's underlying resource (limit->val.resname, e.g. "slots") had the identical `if (rc==0) return -ENOENT;` pattern, vulnerable to the same rc convention mismatch (not hit in this specific trace only because "slots" was already registered by the time it was reached, but latent). (3) `if (is_host_based_limit(resmgr, limit)) { shared = 0; }` checked bare truthiness of a function that can return a negative errno -- a non-zero, therefore truthy, value -- so a transient is_host_based_limit() failure would have incorrectly flagged a limit as host-based.

## Fix
FIXED (2026-09-07). All three corrected in instantiate_limit(): (1) `if (vres->vres == NULL) { add_vres(...); }` replaces the rc<0/rc==0 checks -- vres->vres is calloc'd NULL and only ever reassigned by a successful key_find, the same reliable-signal pattern as bug-1786's fix. (2) `if (vres->res == NULL) { return -ENOENT; }` replaces the equivalent rc<0/rc==0 pair for the resource-existence check. (3) `is_host_based_limit(resmgr, limit) > 0` replaces the bare truthiness check. No new unit test added (same reasoning as bug-1786: this function's correctness is now covered by full live E2E verification, and hand-building a resmgr+sched_core fixture for a unit test was judged not worth the fragility versus the live proof already obtained -- see bug-1786/1789 discussion). Full scheduler suite: 76/77 (pre-existing bug-1762). LIVE-VERIFIED: combined with bug-1784/1785/1786/1787, all 7 limits in limits.yaml (ug1_slots, ug2_slots_per_user, night_mem_pct, hg1_slots_per_host, ug1_normal_slots, limit1, limits2) now correctly appear in the trace and complete matching+instantiation for every job submission on a completely fresh, never-before-touched cluster deploy -- confirmed reproducible across 3 independent from-scratch redeploys, ruling out any deploy-specific or rejoin-specific artifact.

## Verification
_Not recorded (migrated from buglog.json)._

## References
- Related: bug-1495, bug-1784, bug-1785, bug-1786, bug-1787, bug-1789
- Gitea: #46