Leave moving the plans after a build's outcome to the look in the serving controller, so a release's retried send no longer runs on the event loop (issue 1708)

cmd/mesh-controller/outcome_off_the_loop_test.go

@@ -104,3 +104,39 @@ func TestTheRecordsSettleAnOutcomeWithWhatTheBuildDid(t *testing.T) {
 		t.Fatalf("an outcome's words were kept for a second settle: %q", got)
 	}
 }
+
+// 1708/AC5: given a serving controller (its look at the plans running), when an outcome was taken into the plans,
+// then moving them (a release's sends, which may retry for minutes) is left to the look, off the event loop
+// (2026-10-21 14:28:40 to 14:32:10: the loop sent okioki's release to g14 after mesh-delivery-builder's outcome).
+func TestAnOutcomeLeavesMovingThePlansToTheLook(t *testing.T) {
+	l := withLooker(t)
+	moved := false
+	advanceAfterOutcome(func() { moved = true })
+	if moved {
+		t.Fatal("the plans were moved on the event loop after an outcome, where a send that retries holds every message")
+	}
+	select {
+	case <-l.signal:
+	default:
+		t.Fatal("the look was not asked to move the plans after an outcome")
+	}
+}
+
+// 1708/AC5: given no look running (a command, which has no event loop), when an outcome was taken, then the plans are
+// moved at once, as before.
+func TestAnOutcomeMovesThePlansWhereNoLookRuns(t *testing.T) {
+	lookerMu.Lock()
+	before := theLooker
+	theLooker = nil
+	lookerMu.Unlock()
+	t.Cleanup(func() {
+		lookerMu.Lock()
+		theLooker = before
+		lookerMu.Unlock()
+	})
+	moved := false
+	advanceAfterOutcome(func() { moved = true })
+	if !moved {
+		t.Fatal("with no look running, an outcome left the plans unmoved")
+	}
+}

cmd/mesh-controller/plan_looks.go

@@ -136,6 +136,18 @@ func askToLook() {
 	}
 }
 
+// askedToLook asks the serving controller's look at the plans, and says whether there was one to ask.
+func askedToLook() bool {
+	lookerMu.RLock()
+	l := theLooker
+	lookerMu.RUnlock()
+	if l == nil {
+		return false
+	}
+	l.ask()
+	return true
+}
+
 // startPlanLooks starts the look at the open plans, and asks for the first: the controller took the lease, and a
 // plan left by a replaced controller resumes from there (ADR 0406 §6). It replaces the rollout's 30 second ticker.
 // It answers a channel that is closed once the look has returned after the context ended, for a test that restores what

cmd/mesh-controller/release_plan.go

@@ -761,7 +761,19 @@ func planBuiltSaying(ctx context.Context, open *stores, module, commit, failed s
 			fmt.Printf("%s: %s; the tiers after it are not asked\n", p.ID, p.Note)
 		}
 	}
-	advanceHeld(ctx, open)
+	advanceAfterOutcome(func() { advanceHeld(ctx, open) })
+}
+
+// advanceAfterOutcome moves the plans after an outcome was taken into them: **in the serving controller, by asking
+// the look** (novox/hq issue 1708). The outcome is taken on the event loop, and moving the plans may send machines
+// their declarations, a release's send retried for minutes among them; done here it held every report, build and
+// merge behind it (2026-10-21 14:28:40 to 14:32:10). The look runs off the loop, holding the plans itself. Where no
+// look runs (a command, which has no event loop) the plans are moved at once, as before.
+func advanceAfterOutcome(advance func()) {
+	if askedToLook() {
+		return
+	}
+	advance()
 }
 
 // startedBeside is the id of a started walk open beside this one that it is related to — a merge's walk past