scheduler audit P1: picker hook validation + rejection WARNs + sim bootstrap by name

P1-1: sched_resolve_job_picker() now validates all nine MUST hooks --
the four state-change hooks (on_queue_update/on_job_push/
on_job_state_change/on_job_update) were called unconditionally by
core_events.c, scheduler.c and snapshot_load.c but never validated at
resolution time, so a picker omitting one segfaulted on its first event
instead of failing startup validation with -EINVAL. Doc comment on
core.h's declaration updated to match.

P1-2: handle the picker hooks' return values instead of dropping them.
The known real producer of a rejection is builtin_fcfs's "queue not
(yet) in the candidate registry" -EINVAL: the job stayed tracked in
core->jobs but was never a scheduling candidate, with no log at all --
invisible forever (no dispatch, no PEND reason, nothing). Five sites in
core_events.c now WARN on rc < 0: the JOBS_PUSH fresh-job site plus a
root-cause WARN in core_upsert_queue (a rejected queue makes every job
in it fail too), both JOBS_PUSH resync-merge on_job_state_change sites,
JOB_STATE_CHANGE and JOB_UPDATE. All non-fatal: the push itself still
succeeds and the job stays tracked.

P1-3: sim_bootstrap_picker() is now name-driven with an explicit WARN
and graceful degrade for any picker name that has no sim-viable builtin
picker -- including the legacy "xce_sched_fcfs", whose job_elect_fn
reads plugin->sched (an xce_scheduler_t* the sim driver never has, and
which plugin_register_core() deliberately leaves NULL with no legacy
wrapper), so bootstrapping it would crash the rebuild walk on
picker_iface == NULL. Previously an unknown name silently returned
while sim still warned downstream. A short experiment with bootstrapping
the legacy plugin via an fcfs_new_plugin() factory was reverted: making
that plugin core-only-viable is a refactor of a plugin slated for
removal (audit P2 #18), not a bootstrap fix.

Tests:
- sched_picker_wiring_test: new test_picker_missing_state_change_hooks_
  fails_with_einval wires the five ORIGINAL MUST hooks and leaves ONLY
  the four state-change hooks NULL, so the asserted -EINVAL can only
  come from the new checks.
- sched_core_events_test: new test_jobs_push_picker_rejection_still_
  tracks_job_and_succeeds proves the push succeeds, the hook fires
  once, and sched_get_job() still resolves the job after a rejection.

P2 items from the same audit are recorded (not fixed) in gaps.md
section 七 (items 18-21): legacy fcfs zombie, dead scaffolding fields,
preemption without a producer, job-priority chain.

134/134 tests pass.

Co-Authored-By: Claude Code <noreply@anthropic.com>

gaps.md

@@ -5,6 +5,8 @@
 > 约定：本文档只做记录，未做任何代码改动。
 >
 > **2026-10-20 增补**：openmpi 回归（OS openmpi 4.1.6 跨机跑通，见 memory xce-mpi-regression）与全框架评审后新增"五、架构层改进项"（11–17）与"六、构建/分发系统"，原有 1–10 维持不变。
+>
+> **2026-10-22 增补**：调度框架 picker 子系统专项审计（本次 P1 修复见 git log；本节新增审计中**未修**的 P2 项，编号顺延为 18–21，见文末"七"）。
 
 ---
 
@@ -161,6 +163,28 @@ main_reason 契约在两个代码库各自演化，scheduler-framework 合并时
 
 ---
 
+## 七、调度框架 picker 子系统审计遗留项（2026-10-22 增补，P2 未修）
+
+> 来源：调度框架专项审计（"作业调度除了 FCFS 还有哪些？调度框架本身有什么要修补的？"）。P1 三项已在本次修复：sched_resolve_job_picker 九钩子全量校验、core_events.c 五处 on_job_push/on_job_state_change/on_job_update/on_queue_update 拒绝 WARN、sim_picker.c 按名字 bootstrap（仅 builtin_fcfs；legacy "xce_sched_fcfs" 明确不支持——其 job_elect_fn 读 plugin->sched，sim 无 xce_scheduler_t 可给，见 sim_picker.c 文件头）。以下为 P2，**只记录未动**。
+
+### 18. legacy fcfs 插件（僵尸）——与"四"中"legacy fcfs 插件仍注册"同一主体
+- register_fcfs() 每次启动注册 "xce_sched_fcfs"（deprecated job_elect_fn 钩子），注册后不选中就无用，选中则走 fcfs_elect_job 的 sleep(1) 死循环。
+- 本次审计确认它还有一层问题：插件只认 plugin->sched（xce_scheduler_t*），plugin_register_core() 不做 legacy 包装也不设 sched——sim 模式/任何 core-only 调用方都无法安全运行它。sim_picker.c 的 bootstrap 因此明确拒绝该名字。
+- **处置建议**：builtin_fcfs 已完整覆盖 FCFS 语义，可直接删 register_fcfs() 启动注册与整个 fcfs.c（连带 plugin.c 的 legacy_picker_wrapper_iface 与 sched_election.c 的 job_elect_fn 委托分支一起收缩）。
+
+### 19. 死脚手架字段：queue->job_pick_plugin / queue->project_name / queue->resreq
+- core_build_queue()/make_sched_queue() 都把这些字段显式置 NULL（core_events.c:385-387、schedobj.c），注释自认"无 wire-config 来源，后续任务接线"。
+- 全库无生产者无消费者（仅测试断言 NULL）。builtin_fcfs 的队列级 per-queue picker 定制（如果有此需求）就挂在这个字段上。
+- **处置建议**：要么接 config（queue conf 加字段一路穿到 wire schema），要么删字段。留着会让下一个读代码的人以为 per-queue picker 已可用。
+
+### 20. 抢占决策类型有实现无生产者（即"一、2"同一条，从 picker 框架角度再记一笔）
+- make_preempt_decision()（decision.c:35）+ XCE_DECISION_PREEMPT 类型链路完整，仅 testsuite 调用。picker 的 iface 里也没有任何"抢占回调"设计位——真做抢占时 picker/allocator 契约需要扩。
+
+### 21. 作业级优先级（即"一、1"，审计复核确认范围不变）
+- job_submit_data_t 无 priority 字段（types.h）、convert.go modelJobToSubmit 丢弃 JobPriority、core_build_job 硬编码 job->priority=0（core_events.c:353 FIXME）、builtin_fcfs 的 priority 降序比较器因此是死代码。修复面=wire schema + Go API 提交路径 + core_events/schedobj 填充 + （可选）replay/snapshot 携带 priority，四段都要动。
+
+---
+
 ## 附：排查方法论备忘（可复用）
 
 - **gdb 活体结构遍历**：`static xce_scheduler_t sched`（main.c:202）二进制缺完整 DWARF 时，按裸地址 `x/64gx` dump，手工映射 kvmgr {key_type@0, nslots@4, kvtab@8, data@16} 与 xzarray_t {count@0, caps@8, delta@16, pos@24, data@32, killer@40}（zarray.c:392 实际布局，非 include/zarray.h 旧布局），用已知常量（queues nslots=59、workers 5381、delta=64）校验。

src/scheduler/include/core.h

@@ -383,8 +383,12 @@ extern int sched_queue_is_ready(xce_sched_queue_t*);
  * (core->plugins, the same plugin_register()/key_find() mechanism every
  * other plugin category uses) and validates the result actually implements
  * the picker MUST hooks (xce_job_picker_iface_t: next_job, begin_session,
- * end_session, on_dispatch, on_pend). Returns 0 and sets *out on success; a
+ * end_session, on_dispatch, on_pend, plus the four state-change hooks
- * negative errno on failure:
+ * on_queue_update, on_job_push, on_job_state_change, on_job_update --
+ * core_events.c/scheduler.c/snapshot_load.c call those unconditionally on
+ * any resolved picker, so a picker missing one would crash on its first
+ * state-change event rather than fail startup validation). Returns 0 and
+ * sets *out on success; a negative errno on failure:
  *   -EINVAL  bad arguments, or core->job_pick_plugin is unset (NULL), or
  *            the name IS registered but is not a usable picker
  *   -ENOENT  the configured name is not registered at all

src/scheduler/src/core_events.c

@@ -416,6 +416,7 @@ static void core_upsert_queue(xce_sched_core_t* core, xce_sched_plugin_t* picker
                               xce_queue_t* updated)
 {
     xce_sched_queue_t* q;
+    int                qrc;
 
     if ((updated == NULL) || (updated->queue == NULL)) {
         WARN("%s NULL queue payload", __func__);
@@ -456,7 +457,18 @@ static void core_upsert_queue(xce_sched_core_t* core, xce_sched_plugin_t* picker
     }
 
     if (picker != NULL) {
-        picker->picker_iface->on_queue_update(picker, q);
+        /* A rejected on_queue_update leaves the queue out of the picker's
+         * candidate registry -- every job in it then gets builtin_fcfs's
+         * "unknown queue" -EINVAL from on_job_push too (each one WARNed by
+         * the JOBS_PUSH site). Log this root cause as well so the first
+         * failure is visible in the log rather than only its downstream
+         * echoes. */
+        qrc = picker->picker_iface->on_queue_update(picker, q);
+        if (qrc < 0) {
+            WARN("%s picker rejected queue '%s' (rc=%d) -- its jobs will "
+                 "not be scheduling candidates until it is accepted",
+                 __func__, (q->name != NULL) ? q->name : "?", qrc);
+        }
     }
 }
 
@@ -1048,9 +1060,13 @@ int xce_core_push_events(xce_sched_core_t* core, xce_core_event_t* events,
 
                                 existing->state = job->state;
 
-                                if (picker != NULL) {
+                                rc = picker->picker_iface->on_job_state_change(
-                                    picker->picker_iface->on_job_state_change(
+                                    picker, existing, job->state);
-                                        picker, existing, job->state);
+                                if (rc < 0) {
+                                    WARN("%s JOBS_PUSH: picker rejected "
+                                         "state merge for jobid %s "
+                                         "(rc=%d)",
+                                         __func__, jobidStr, rc);
                                 }
                             }
                         /* bug-1860: no refusal for a non-RUN, non-terminal
@@ -1075,9 +1091,12 @@ int xce_core_push_events(xce_sched_core_t* core, xce_core_event_t* events,
 
                             existing->state = job->state;
 
-                            if (picker != NULL) {
+                            rc = picker->picker_iface->on_job_state_change(
-                                picker->picker_iface->on_job_state_change(
+                                picker, existing, job->state);
-                                    picker, existing, job->state);
+                            if (rc < 0) {
+                                WARN("%s JOBS_PUSH: picker rejected "
+                                     "state merge for jobid %s (rc=%d)",
+                                     __func__, jobidStr, rc);
                             }
                         }
                     }
@@ -1107,7 +1126,29 @@ int xce_core_push_events(xce_sched_core_t* core, xce_core_event_t* events,
                 }
 
                 if (picker != NULL) {
-                    picker->picker_iface->on_job_push(picker, job);
+                    int prc = picker->picker_iface->on_job_push(picker, job);
+
+                    /* The job IS registered in core->jobs now, but a failed
+                     * on_job_push means it is NOT a picker candidate -- with
+                     * the return value dropped it would sit invisible
+                     * forever (no dispatch, no PEND reason, nothing). The
+                     * known real producer of a rejection is builtin_fcfs's
+                     * "queue not (yet) in the picker's candidate registry"
+                     * (-EINVAL); WARN so the operator can see the orphan
+                     * instead of it vanishing silently. Non-fatal: the next
+                     * event touching this job (e.g. a JOB_UPDATE) re-runs
+                     * the picker's insert path. */
+                    if (prc < 0) {
+                        char jobidStr[64];
+
+                        fmt_jobid(jobidStr, sizeof(jobidStr), job->jobid);
+                        WARN("%s JOBS_PUSH: picker rejected jobid %s "
+                             "(queue '%s', rc=%d) -- job is tracked but not "
+                             "a scheduling candidate",
+                             __func__, jobidStr,
+                             (job->queue != NULL) ? job->queue->name : "?",
+                             prc);
+                    }
                 }
             }
             break;
@@ -1323,8 +1364,16 @@ int xce_core_push_events(xce_sched_core_t* core, xce_core_event_t* events,
             job->state = new_state;
 
             if (picker != NULL) {
-                picker->picker_iface->on_job_state_change(picker, job,
+                rc = picker->picker_iface->on_job_state_change(picker, job,
-                                                          new_state);
+                                                               new_state);
+                if (rc < 0) {
+                    char jobidStr[64];
+
+                    fmt_jobid(jobidStr, sizeof(jobidStr), jobid);
+                    WARN("%s JOB_STATE_CHANGE: picker rejected jobid %s "
+                         "(rc=%d) -- candidate tracking may be stale",
+                         __func__, jobidStr, rc);
+                }
             }
             break;
         }
@@ -1447,7 +1496,17 @@ int xce_core_push_events(xce_sched_core_t* core, xce_core_event_t* events,
             }
 
             if (picker != NULL) {
-                picker->picker_iface->on_job_update(picker, job);
+                rc = picker->picker_iface->on_job_update(picker, job);
+                if (rc < 0) {
+                    char jobidStr[64];
+
+                    /* bug-1591: see repl_info.c's repl_info_worker_one()
+                     * comment on fmt_jobid(). */
+                    fmt_jobid(jobidStr, sizeof(jobidStr), updated->jobid);
+                    WARN("%s JOB_UPDATE: picker rejected jobid %s (rc=%d) "
+                         "-- candidate tracking may be stale",
+                         __func__, jobidStr, rc);
+                }
             }
             break;
         }

src/scheduler/src/plugins/fcfs.c

@@ -363,6 +363,12 @@ static int fcfs_commit(xce_sched_plugin_t* plugin, xce_decision_t* decision)
 
 int register_fcfs(void* sched)
 {
+    /* register_fcfs() keeps the template inline (unlike
+     * register_builtin_fcfs()'s builtin_fcfs_new_plugin() extraction):
+     * no core-only caller exists -- sim_picker.c's bootstrap deliberately
+     * does NOT support this legacy plugin (job_elect_fn-only, reads
+     * plugin->sched), and this file is itself slated for removal with the
+     * legacy fcfs zombie (scheduling-audit P2). */
     static xce_sched_plugin_t fcfs_plugin = {
         .name = "xce_sched_fcfs",
         .hooks

src/scheduler/src/schedobj.c

@@ -478,12 +478,27 @@ int sched_resolve_job_picker(xce_sched_core_t* core, xce_sched_plugin_t** out)
         return (rc < 0) ? rc : -ENOENT;
     }
 
+    /* All nine are MUST hooks per plugin.h's iface contract: the session
+     * set (next_job/begin_session/end_session) and post-allocation set
+     * (on_dispatch/on_pend) are dispatched through the resolved pointer
+     * here, while the four state-change hooks are called unconditionally
+     * by core_events.c (on_queue_update/on_job_push/on_job_state_change/
+     * on_job_update), scheduler.c (sched_init_queues' on_queue_update) and
+     * snapshot_load.c (rebuild walk) -- so a picker that leaves any of
+     * them NULL must be rejected HERE, at resolution time, not segfault on
+     * its first event. The optional hooks (on_config/on_job_rusage) are
+     * deliberately NOT checked -- every call site guards those with
+     * != NULL. */
     if ((plugin == NULL) || (plugin->picker_iface == NULL)
         || (plugin->picker_iface->next_job == NULL)
         || (plugin->picker_iface->begin_session == NULL)
         || (plugin->picker_iface->end_session == NULL)
         || (plugin->picker_iface->on_dispatch == NULL)
-        || (plugin->picker_iface->on_pend == NULL)) {
+        || (plugin->picker_iface->on_pend == NULL)
+        || (plugin->picker_iface->on_queue_update == NULL)
+        || (plugin->picker_iface->on_job_push == NULL)
+        || (plugin->picker_iface->on_job_state_change == NULL)
+        || (plugin->picker_iface->on_job_update == NULL)) {
         return -EINVAL;
     }
 

src/scheduler/src/sim_picker.c

@@ -43,6 +43,25 @@
  * replays that same rebuild walk a second time, against whichever picker
  * it just registered, mirroring xce_sched_core_load_snapshot()'s own
  * queues-before-jobs ordering (snapshot_load.c) exactly.
+ *
+ * Picker-name resolution (audit fix): the bootstrap is NAME-DRIVEN across
+ * the built-in picker set -- "builtin_fcfs" registers the native picker,
+ * as before. Any other name (WARN now, instead of the old silent return)
+ * stays unresolvable -- sched_resolve_job_picker() legitimately fails
+ * downstream and the picker thread degrades gracefully, the same
+ * documented behavior xce_sched_core_load_snapshot() already establishes
+ * for an unresolvable picker (sim.h's own doc comment).
+ *
+ * The legacy "xce_sched_fcfs" (plugins/fcfs.c, the other builtin picker)
+ * is deliberately NOT bootstrap-able here, despite being in the builtin
+ * set: it is a job_elect_fn-only plugin whose elect loop reads
+ * plugin->sched -- an xce_scheduler_t* the simulation driver never has
+ * (plugin_register_core() deliberately leaves it NULL, and applies no
+ * legacy wrapper either, so the rebuild walk below would dereference
+ * picker_iface == NULL first). Making the legacy plugin sim-viable would
+ * mean retyping it onto plugin->core -- a refactor of a plugin already
+ * slated for removal (legacy fcfs zombie), not a bootstrap-name fix. A
+ * replay recorded under that name degrades with an explicit WARN instead.
  */
 
 /* Consumed by sim_loop.c via a plain `extern` declared there -- same
@@ -65,21 +84,25 @@ void sim_bootstrap_picker(xce_sched_sim_driver_t* sim)
          * legitimately fails for it downstream, and the picker thread
          * degrades gracefully, the same documented behavior
          * xce_sched_core_load_snapshot() already establishes for an
-         * unresolvable picker (sim.h's own doc comment). */
+         * unresolvable picker (sim.h's own doc comment). This includes
+         * the legacy "xce_sched_fcfs" (see this file's header comment). */
+        WARN("%s replay recorded under picker '%s' -- no sim-viable "
+             "builtin picker of that name to bootstrap; scheduling will "
+             "be inert",
+             __func__, sim->core.job_pick_plugin);
         return;
     }
 
     plugin = builtin_fcfs_new_plugin();
     if (plugin == NULL) {
-        ERROR("%s out of memory building the builtin_fcfs plugin instance",
+        ERROR("%s out of memory building the %s plugin instance", __func__,
-              __func__);
+              sim->core.job_pick_plugin);
         return;
     }
 
     if (plugin_register_core(&(sim->core), plugin) < 0) {
-        ERROR("%s failed to register builtin_fcfs against the simulation "
+        ERROR("%s failed to register %s against the simulation core",
-              "core",
+              __func__, plugin->name);
-              __func__);
         free(plugin);
         return;
     }

src/scheduler/testsuite/test_core_events.c

@@ -185,6 +185,7 @@ typedef struct {
     int                job_update_calls;
     int                queue_update_calls;
     int                job_rusage_calls;
+    int                job_push_rc;   /* value the spy's on_job_push returns */
     xce_conf4sched_t*  last_config;
     xce_sched_job_t*   last_job_push;
     xce_sched_job_t*   last_job_state_change_job;
@@ -238,7 +239,7 @@ static int test_on_job_push(void* picker, xce_sched_job_t* job)
     (void)picker;
     g_counts.job_push_calls++;
     g_counts.last_job_push = job;
-    return 0;
+    return g_counts.job_push_rc;
 }
 
 static int test_on_job_state_change(void* picker, xce_sched_job_t* job,
@@ -1960,6 +1961,50 @@ static void test_push_events_zero_nevents_is_a_valid_noop(void)
     TEST_ASSERT_EQUAL_INT(0, rc);
 }
 
+/* Picker-rejects-push audit fix: when on_job_push() returns <0 (the known
+ * producer is builtin_fcfs's "queue not in the picker's candidate registry"
+ * -EINVAL), the job is registered in core->jobs but is NOT a picker
+ * candidate -- with the return value silently dropped it sat invisible
+ * forever (no dispatch, no PEND reason, no log). xce_core_push_events() now
+ * WARNs (the operator-facing signal) but the push itself still succeeds:
+ * the event batch returns 0 and the job stays tracked -- rejection is the
+ * picker's prerogative, not a transport failure. */
+static void
+test_jobs_push_picker_rejection_still_tracks_job_and_succeeds(void)
+{
+    xce_sched_core_t core;
+    xce_core_event_t event;
+    xce_job_t*       job1;
+    int              rc;
+
+    fixture_init(&core, &g_full_plugin);
+
+    job1 = make_job(71, JOB_STAT_PEND, "normal", "alice", "proj1");
+
+    memset(&event, 0, sizeof(event));
+    event.type              = XCE_CORE_EVENT_JOBS_PUSH;
+    event.u.jobs_push.njobs = 1;
+    event.u.jobs_push.jobs  = &job1;
+
+    /* Simulate builtin_fcfs's "unknown queue" rejection. */
+    g_counts.job_push_rc = -EINVAL;
+
+    rc = xce_core_push_events(&core, &event, 1);
+
+    /* The push still succeeds and the hook still fired -- the WARN (not
+     * directly assertable here) is the only visible change. The hook
+     * receives the CORE-BUILT object (core_build_job()), not the wire
+     * payload -- same identity sched_get_job() resolves. */
+    TEST_ASSERT_EQUAL_INT(0, rc);
+    TEST_ASSERT_EQUAL_INT(1, g_counts.job_push_calls);
+    TEST_ASSERT_EQUAL_PTR(sched_get_job(&core, 71), g_counts.last_job_push);
+
+    /* The job remains tracked in core->jobs regardless of the rejection. */
+    TEST_ASSERT_NOT_NULL(sched_get_job(&core, 71));
+
+    g_counts.job_push_rc = 0;
+}
+
 int main(void)
 {
     UNITY_BEGIN();
@@ -1990,5 +2035,6 @@ int main(void)
     RUN_TEST(test_push_events_null_core_returns_einval);
     RUN_TEST(test_push_events_null_events_with_positive_nevents_returns_einval);
     RUN_TEST(test_push_events_zero_nevents_is_a_valid_noop);
+    RUN_TEST(test_jobs_push_picker_rejection_still_tracks_job_and_succeeds);
     return UNITY_END();
 }

src/scheduler/testsuite/test_picker_wiring.c

@@ -515,6 +515,75 @@ test_legacy_and_native_pickers_coexist_and_resolve_independently(void)
     TEST_ASSERT_NULL(resolved->job_elect_fn);
 }
 
+/* Picker-resolution audit fix: the four state-change hooks
+ * (on_queue_update/on_job_push/on_job_state_change/on_job_update) are MUST
+ * hooks per plugin.h's iface contract -- core_events.c/scheduler.c/
+ * snapshot_load.c call them UNCONDITIONALLY on any resolved picker, so a
+ * picker omitting one segfaulted on its first event rather than failing
+ * startup validation. They must be part of sched_resolve_job_picker()'s
+ * validation, same as the five original MUST hooks. The iface below wires
+ * everything EXCEPT those four (incl. the optional on_config/on_job_rusage
+ * left NULL, as call sites NULL-guard those), so the -EINVAL the test
+ * asserts can only come from the four NEW checks. */
+static int test_wired_noop_int(void* picker)
+{
+    (void)picker;
+    return 0;
+}
+
+static xce_sched_job_t* test_wired_next_job(void* picker)
+{
+    (void)picker;
+    return NULL;
+}
+
+static int test_wired_jobid_noop(void* picker, uint64_t jobid)
+{
+    (void)picker;
+    (void)jobid;
+    return 0;
+}
+
+static xce_job_picker_iface_t g_session_hooks_only_iface = {
+    .init                = NULL,
+    .fini                = NULL,
+    .begin_session       = test_wired_noop_int,
+    .next_job            = test_wired_next_job,
+    .end_session         = test_wired_noop_int,
+    .on_dispatch         = test_wired_jobid_noop,
+    .on_pend             = test_wired_jobid_noop,
+    .on_queue_update     = NULL,
+    .on_job_push         = NULL,
+    .on_job_state_change = NULL,
+    .on_job_update       = NULL,
+    .on_config           = NULL,
+    .on_job_rusage       = NULL,
+};
+
+static void
+test_picker_missing_state_change_hooks_fails_with_einval(void)
+{
+    xce_scheduler_t     sched;
+    xce_sched_plugin_t* partial = NULL;
+    xce_sched_plugin_t* resolved = NULL;
+    int                 rc;
+
+    fixture_init(&sched);
+
+    /* A picker wiring the five original MUST hooks but leaving all four
+     * state-change hooks NULL must be rejected at resolution time. */
+    partial = (xce_sched_plugin_t*)calloc(1, sizeof(*partial));
+    TEST_ASSERT_NOT_NULL(partial);
+    partial->name         = "partial_state_change_picker";
+    partial->picker_iface = &g_session_hooks_only_iface;
+    TEST_ASSERT_GREATER_OR_EQUAL(0, plugin_register(&sched, partial));
+
+    sched.core.job_pick_plugin = "partial_state_change_picker";
+    rc = sched_resolve_job_picker(&sched.core, &resolved);
+    TEST_ASSERT_EQUAL_INT(-EINVAL, rc);
+    TEST_ASSERT_NULL(resolved);
+}
+
 int main(void)
 {
     UNITY_BEGIN();
@@ -533,5 +602,6 @@ int main(void)
     RUN_TEST(test_legacy_and_native_pickers_coexist_and_resolve_independently);
     RUN_TEST(
         test_legacy_picker_deprecation_flagged_on_selection_not_registration);
+    RUN_TEST(test_picker_missing_state_change_hooks_fails_with_einval);
     return UNITY_END();
 }