cmd/mesh-controller/builder_says_test.go

@@ -127,7 +127,6 @@ func TestAnOpenWalkWaitingOnAnUnreferencedKeyIsAskedOfBuildAgent(t *testing.T) {
 
 	// Not said: handed back, and the next look asks build-agent.
 	p, byName, keys := walk()
-	keys.notSaid = true
 	theBuilderSays(t, false, nil)
 	asked := askingBuildAgent(t)
 	changed, err := settleKeys(t.Context(), records, keys, p, p.Tiers[0], take)
@@ -154,7 +153,8 @@ func TestAFailedKeyOfABuilderThatDoesNotSayFailsNoWalk(t *testing.T) {
 	askModule(t.Context(), p, "sudo", byName)
 	_ = byName
 	fp := "src2:" + strings.Repeat("f", 64)
-	keys := planKeysOf{notSaid: true, values: map[string]sdkdelivery.Module{"sudo@c0ffee0123456789": {FP2: fp}},
+	theBuilderSays(t, false, nil)
+	keys := planKeysOf{values: map[string]sdkdelivery.Module{"sudo@c0ffee0123456789": {FP2: fp}},
 		keys: map[string]builderkeys.Key{"sudo": {Module: "sudo", Fingerprint: fp, Found: true,
 			Build: sdkdelivery.BuilderBuild{State: sdkdelivery.BuildFailed, Error: "not stored: tools: no reference"}}}}
 	if _, err := settleKeys(t.Context(), recordsOf{}, keys, p, p.Tiers[0], func(string, sdkdelivery.Module, string) {}); err != nil {
@@ -221,3 +221,23 @@ func TestTheAskGuardUsesTheSayTheWalkRead(t *testing.T) {
 		}
 	}
 }
+
+// 1886 merge check hang: the look must judge an ask and a settle by one say. A settle that read the say from another
+// source than the ask (the bus's bucket, against the walk's read) handed a module back, the next ask took it from its key
+// again, and the look's loop never ended: walk_from_keys_integration_test hung.
+func TestTheSettleJudgesByTheSameSayAsTheAsk(t *testing.T) {
+	theBuilderSays(t, true, nil)
+	p, _ := aWalkOfOne("sudo")
+	p.Modules["sudo"] = &inventory.PlanModule{}
+	askModule(t.Context(), p, "sudo", map[string]inventory.Entry{"sudo": {Source: inventory.Source{Repository: "novox/mesh-catalog", Path: "modules/sudo", Ref: "main"}}})
+	fp := "src2:" + strings.Repeat("1", 64)
+	keys := planKeysOf{values: map[string]sdkdelivery.Module{"sudo@c0ffee0123456789": {FP2: fp}},
+		keys: map[string]builderkeys.Key{"sudo": {Module: "sudo", Fingerprint: fp, Found: true,
+			Build: sdkdelivery.BuilderBuild{State: sdkdelivery.BuildBuilding, By: "shanks"}}}}
+	if _, err := settleKeys(t.Context(), recordsOf{}, keys, p, p.Tiers[0], func(string, sdkdelivery.Module, string) {}); err != nil {
+		t.Fatal(err)
+	}
+	if s := p.Modules["sudo"]; !s.Key || s.State != "asked" {
+		t.Fatalf("the settle judged by another say than the ask's: %+v", s)
+	}
+}

cmd/mesh-controller/plan_keys.go

@@ -47,8 +47,6 @@ var buildersOwn = func(module string) bool { return buildAgentsOwn[module] }
 type planKeyReads interface {
 	ModuleAt(ctx context.Context, module, commit string) (sdkdelivery.Module, error)
 	Build(ctx context.Context, module, fp string) (builderkeys.Key, error)
-	// SaysReferences is whether a running builder says it writes references (builderkeys.Reader.SaysReferences).
-	SaysReferences(ctx context.Context) (bool, error)
 }
 
 // builderSayKey carries, on an ask's context, the builder's say the walk read before asking (withBuilderSay).
@@ -135,7 +133,9 @@ func settleKeys(ctx context.Context, inv keyRecords, keys planKeyReads, p *inven
 			changed = true
 		}
 	}
-	says, err := keys.SaysReferences(ctx)
+	// One say for the ask and the settle (builderSaysReferences): two sources that differ hand a module back and take it
+	// from its key again at every turn of the look, which then never ends.
+	says, err := builderSaysReferences(ctx)
 	if err != nil {
 		return changed, fmt.Errorf("whether the builder writes references cannot be read: %w", err)
 	}

cmd/mesh-controller/plan_keys_test.go

@@ -16,12 +16,8 @@ import (
 type planKeysOf struct {
 	values map[string]sdkdelivery.Module // by module + "@" + commit
 	keys   map[string]builderkeys.Key
-	// notSaid is a builder that does not say it writes references (issue 1886); the zero value says it.
-	notSaid bool
 }
 
-func (k planKeysOf) SaysReferences(context.Context) (bool, error) { return !k.notSaid, nil }
-
 func (k planKeysOf) ModuleAt(_ context.Context, module, commit string) (sdkdelivery.Module, error) {
 	if v, ok := k.values[module+"@"+commit]; ok {
 		return v, nil