diff --git a/modules/mesh-build-go/buildstep/go.mod b/modules/mesh-build-go/buildstep/go.mod
index e9d32952a..77b28476c 100644
--- a/modules/mesh-build-go/buildstep/go.mod
+++ b/modules/mesh-build-go/buildstep/go.mod
@@ -3,6 +3,7 @@ module git.novox.be/novox/mesh-catalog/modules/mesh-build-go/buildstep
 go 1.26.0
 
 require (
+	git.novox.be/novox/mesh-contracts/go/seats/meshmoduleassigner v0.0.0-00010101000000-000000000000
 	git.novox.be/novox/mesh-delivery/contracts/go/clients/containerimageregistryclient v0.0.0-00010101000000-000000000000
 	git.novox.be/novox/mesh-delivery/contracts/go/clients/gopackageregistryclient v0.0.0-00010101000000-000000000000
 	git.novox.be/novox/mesh-delivery/contracts/go/clients/npmpackageregistryclient v0.0.0-00010101000000-000000000000
diff --git a/modules/mesh-build-go/buildstep/publish.go b/modules/mesh-build-go/buildstep/publish.go
index 06e080ae8..a83de94df 100644
--- a/modules/mesh-build-go/buildstep/publish.go
+++ b/modules/mesh-build-go/buildstep/publish.go
@@ -15,6 +15,7 @@ import (
 	"os"
 	"strings"
 
+	assigner "git.novox.be/novox/mesh-contracts/go/seats/meshmoduleassigner"
 	imageclient "git.novox.be/novox/mesh-delivery/contracts/go/clients/containerimageregistryclient"
 	goclient "git.novox.be/novox/mesh-delivery/contracts/go/clients/gopackageregistryclient"
 	npmclient "git.novox.be/novox/mesh-delivery/contracts/go/clients/npmpackageregistryclient"
@@ -23,6 +24,7 @@ import (
 	goseat "git.novox.be/novox/mesh-delivery/contracts/go/seats/gopackageregistry"
 	npmseat "git.novox.be/novox/mesh-delivery/contracts/go/seats/npmpackageregistry"
 	ociseat "git.novox.be/novox/mesh-delivery/contracts/go/seats/ociartifactregistry"
+	sdkstep "git.novox.be/novox/mesh-delivery/sdk/buildstep"
 	"git.novox.be/novox/mesh-delivery/sdk/parts"
 )
 
@@ -76,6 +78,41 @@ func SentHow(n int) func(parts.Sent) string {
 // PublishParts publishes in with ps as its parts on seat, through that seat's client: in's fields are the seat's own
 // (the four registry seats share the publish verb's input, design 51), the parts are written by the client.
 func PublishParts(ctx context.Context, call SeatCall, seat string, in reg.PublishInput, ps []parts.Part) (parts.Sent, error) {
+	sent, err := publishParts(ctx, call, seat, in, ps)
+	return sent, HolderSilentOr(call, seat, err)
+}
+
+// AssignerHolders is the verb that tells who holds a seat: `mesh-module-assigner.assignments` with seats
+// (the state seat-holders). The build modules' manifests `invokes` it.
+const AssignerHolders = "seat:" + assigner.Seat + "." + assigner.VerbAssignments
+
+// HolderSilentOr is err, or when it is a seat verb's "no responders" and the assigner names a holder of seat, a
+// sdkstep.HolderSilent (a Passing: the holder's tool runner is being replaced and answers a moment later, ADR 0664 §1). The
+// bus says "no responders" for a seat nothing holds too, so the words alone are no transport fault: with no holder named, or
+// when the holders cannot be asked, the error stays as it is, said with why, and fails at once.
+func HolderSilentOr(call SeatCall, seat string, err error) error {
+	if err == nil || !strings.Contains(strings.ToLower(err.Error()), "no responders") {
+		return err
+	}
+	raw, aerr := call(AssignerHolders, map[string]any{"seats": assigner.AssignmentsInputSeatsTrue})
+	if aerr != nil {
+		return fmt.Errorf("%w (who holds %s could not be asked: %v)", err, seat, aerr)
+	}
+	var answer struct {
+		Seats []assigner.SeatHolders `json:"seats"`
+	}
+	if jerr := json.Unmarshal(raw, &answer); jerr != nil {
+		return fmt.Errorf("%w (who holds %s was answered in what is not read: %v)", err, seat, jerr)
+	}
+	for _, sh := range answer.Seats {
+		if sh.Seat == seat && len(sh.Holders) > 0 {
+			return fmt.Errorf("%w: %w", err, &sdkstep.HolderSilent{Seat: seat, Holder: sh.Holders[0].Module, Node: sh.Holders[0].Node})
+		}
+	}
+	return fmt.Errorf("%w (nothing holds %s)", err, seat)
+}
+
+func publishParts(ctx context.Context, call SeatCall, seat string, in reg.PublishInput, ps []parts.Part) (parts.Sent, error) {
 	switch seat {
 	case ImageSeat:
 		s, err := imageclient.Publish(ctx, imageclient.Call(call), in, ps)
diff --git a/modules/mesh-build-go/cmd/mesh-build-go/build.go b/modules/mesh-build-go/cmd/mesh-build-go/build.go
index cb4eab097..466fae221 100644
--- a/modules/mesh-build-go/cmd/mesh-build-go/build.go
+++ b/modules/mesh-build-go/cmd/mesh-build-go/build.go
@@ -178,7 +178,7 @@ func (m *Module) packInto(ctx context.Context, workspace, module, name, artifact
 		return BuildResult{}, fmt.Errorf("packing %s: %w", artifact, err)
 	}
 	if err := m.publishArchive(ctx, name, artifact, kind, digest, archive); err != nil {
-		return BuildResult{}, fmt.Errorf("%s%s: %v", builds.NotStored, artifact, err)
+		return BuildResult{}, fmt.Errorf("%s%s: %w", builds.NotStored, artifact, err)
 	}
 	return BuildResult{Artifact: artifact, Digest: digest, Size: len(archive), Reference: artifactref.SeatReference(ArtifactSeat, name, artifact, digest)}, nil
 }
diff --git a/modules/mesh-build-go/cmd/mesh-build-go/gopackage.go b/modules/mesh-build-go/cmd/mesh-build-go/gopackage.go
index dbeaf4bee..18af8cb04 100644
--- a/modules/mesh-build-go/cmd/mesh-build-go/gopackage.go
+++ b/modules/mesh-build-go/cmd/mesh-build-go/gopackage.go
@@ -82,7 +82,7 @@ func (m *Module) buildGoPackage(ctx context.Context, workspace, dir string, art
 		return res, nil
 	}
 	if err := m.publishOn(ctx, seat, path, "package", version, digest, transferName(path, version, digest), body); err != nil {
-		return BuildResult{}, fmt.Errorf("%s%s: %v", builds.NotStored, art.Name, err)
+		return BuildResult{}, fmt.Errorf("%s%s: %w", builds.NotStored, art.Name, err)
 	}
 	res.Reference = path + "@" + version
 	return res, nil
diff --git a/modules/mesh-build-go/cmd/mesh-build-go/publish_test.go b/modules/mesh-build-go/cmd/mesh-build-go/publish_test.go
index 4f5a587d9..7a37ace2b 100644
--- a/modules/mesh-build-go/cmd/mesh-build-go/publish_test.go
+++ b/modules/mesh-build-go/cmd/mesh-build-go/publish_test.go
@@ -14,6 +14,7 @@ import (
 	"sync"
 	"testing"
 
+	"git.novox.be/novox/mesh-catalog/modules/mesh-build-go/buildstep"
 	registry "git.novox.be/novox/mesh-delivery/contracts/go/seats/containerimageregistry"
 	builds "git.novox.be/novox/mesh-delivery/modules/mesh-delivery-builder/builds"
 	sdkstep "git.novox.be/novox/mesh-delivery/sdk/buildstep"
@@ -139,6 +140,27 @@ func TestARefusedPushFailsTheStepNotStored(t *testing.T) {
 		!strings.Contains(st.Reason, "oci-artifact-registry") {
 		t.Errorf("no holder: the step ended %s: %q", st.State, st.Reason)
 	}
+	// ADR 0664 §1 (issue 1748): "no responders" is the same words for a seat nothing holds and for a holder whose tool runner is
+	// being replaced; the assigner says which. A named holder makes it a transport fault (the bus gives the ask again), none
+	// fails at once naming it.
+	for _, c := range []struct {
+		name, holders string
+		passing       bool
+		words         string
+	}{
+		{"a holder named", `{"seats":[{"seat":"oci-artifact-registry","holders":[{"module":"mesh-registry","node":"novox"}]}],"holds":1}`, true, "the holder is silent: seat oci-artifact-registry, held by mesh-registry on novox"},
+		{"nothing holds it", `{"seats":[{"seat":"go-package-registry","holders":[{"module":"mesh-registry","node":"novox"}]}],"holds":1}`, false, "nothing holds oci-artifact-registry"},
+	} {
+		m.Call = func(key string, _ any) (json.RawMessage, error) {
+			if key == buildstep.AssignerHolders {
+				return json.RawMessage(c.holders), nil
+			}
+			return nil, errors.New("nats: no responders available for request")
+		}
+		if _, st := runBuild(t, m, states, "tools"); st.State != sdkstep.StepFailed || st.Passing != c.passing || !strings.Contains(st.Reason, c.words) {
+			t.Errorf("%s: the step ended %s: %q (passing %v)", c.name, st.State, st.Reason, st.Passing)
+		}
+	}
 }
 
 // 1587-S4 (the lead's decision L9): the packed file is not left on the node once its push answered, a candidate's
diff --git a/modules/mesh-build-go/go.mod b/modules/mesh-build-go/go.mod
index 13f373b82..87a97efea 100644
--- a/modules/mesh-build-go/go.mod
+++ b/modules/mesh-build-go/go.mod
@@ -102,6 +102,7 @@ replace git.novox.be/novox/mesh-catalog/modules/ssh-client/sshkeys => ../ssh-cli
 
 require (
 	git.novox.be/novox/mesh-contracts/health-and-repair/go/seats/meshconditions v0.0.0-00010101000000-000000000000 // indirect
+	git.novox.be/novox/mesh-contracts/go/seats/meshmoduleassigner v0.0.0-00010101000000-000000000000 // indirect
 	git.novox.be/novox/mesh-delivery/contracts/go/clients/gopackageregistryclient v0.0.0-00010101000000-000000000000 // indirect
 	git.novox.be/novox/mesh-delivery/contracts/go/clients/npmpackageregistryclient v0.0.0-00010101000000-000000000000 // indirect
 	git.novox.be/novox/mesh-delivery/contracts/go/clients/ociartifactregistryclient v0.0.0-00010101000000-000000000000 // indirect
diff --git a/modules/mesh-build-go/module.json b/modules/mesh-build-go/module.json
index 850792328..d630360ce 100644
--- a/modules/mesh-build-go/module.json
+++ b/modules/mesh-build-go/module.json
@@ -35,7 +35,8 @@
     "seat:oci-artifact-registry.publish-part",
     "seat:go-package-registry.publish",
     "seat:go-package-registry.publish-part",
-    "seat:mesh-delivery-checker.input"
+    "seat:mesh-delivery-checker.input",
+    "seat:mesh-module-assigner.assignments"
   ],
   "config": {
     "capacity": {
diff --git a/modules/mesh-build-image/cmd/mesh-build-image/compose_test.go b/modules/mesh-build-image/cmd/mesh-build-image/compose_test.go
index b24aa8138..ff7acedf9 100644
--- a/modules/mesh-build-image/cmd/mesh-build-image/compose_test.go
+++ b/modules/mesh-build-image/cmd/mesh-build-image/compose_test.go
@@ -24,7 +24,7 @@ func TestTheModuleInvokesTheImageSeatAndHoldsNoRegistry(t *testing.T) {
 		t.Fatal(err)
 	}
 	if want := []string{"seat:container-image-registry.publish", "seat:container-image-registry.publish-part",
-		"seat:container-image-registry.mirror"}; !slices.Equal(m.Invokes, want) {
+		"seat:container-image-registry.mirror", "seat:mesh-module-assigner.assignments"}; !slices.Equal(m.Invokes, want) {
 		t.Errorf("invokes = %v, want %v", m.Invokes, want)
 	}
 	// The builder's version.numbered for the late publish (ADR 0617 §1), and the seat's outcomes a copy waits on.
diff --git a/modules/mesh-build-image/cmd/mesh-build-image/publish.go b/modules/mesh-build-image/cmd/mesh-build-image/publish.go
index 4af9d4eb7..7295fc11f 100644
--- a/modules/mesh-build-image/cmd/mesh-build-image/publish.go
+++ b/modules/mesh-build-image/cmd/mesh-build-image/publish.go
@@ -136,7 +136,7 @@ func (m *Module) publish(ctx context.Context, workspace, module, local string, r
 		Transfer: buildstep.TransferName(name, q, img.Digest)}
 	sent, err := buildstep.PublishFiles(ctx, m.call(), buildstep.ImageSeat, in, img.Files)
 	if err != nil {
-		return nil, fmt.Errorf("%s%s: %v", builds.NotStored, res.Artifact, err)
+		return nil, fmt.Errorf("%s%s: %w", builds.NotStored, res.Artifact, err)
 	}
 	m.say("published %s on %s: %d of its %d parts sent, the rest held", name, buildstep.ImageSeat, len(sent.Parts), len(img.Files))
 	res.Digest, res.Pushed = img.Digest, true
diff --git a/modules/mesh-build-image/go.mod b/modules/mesh-build-image/go.mod
index 9795b1b99..06309053b 100644
--- a/modules/mesh-build-image/go.mod
+++ b/modules/mesh-build-image/go.mod
@@ -34,6 +34,7 @@ require git.novox.be/novox/mesh-catalog/modules/ssh-client/sshkeys v0.0.0-000101
 replace git.novox.be/novox/mesh-catalog/modules/ssh-client/sshkeys => ../ssh-client/sshkeys
 
 require (
+	git.novox.be/novox/mesh-contracts/go/seats/meshmoduleassigner v0.0.0-00010101000000-000000000000 // indirect
 	git.novox.be/novox/mesh-delivery/contracts/go/clients/gopackageregistryclient v0.0.0-00010101000000-000000000000 // indirect
 	git.novox.be/novox/mesh-delivery/contracts/go/clients/meshcatalogclient v0.0.0-00010101000000-000000000000 // indirect
 	git.novox.be/novox/mesh-delivery/contracts/go/clients/npmpackageregistryclient v0.0.0-00010101000000-000000000000 // indirect
diff --git a/modules/mesh-build-image/module.json b/modules/mesh-build-image/module.json
index b9013f5bc..fa94ba713 100644
--- a/modules/mesh-build-image/module.json
+++ b/modules/mesh-build-image/module.json
@@ -63,7 +63,8 @@
   "invokes": [
     "seat:container-image-registry.publish",
     "seat:container-image-registry.publish-part",
-    "seat:container-image-registry.mirror"
+    "seat:container-image-registry.mirror",
+    "seat:mesh-module-assigner.assignments"
   ],
   "consumes": [
     "mesh-delivery-builder.version.numbered",
diff --git a/modules/mesh-build-node/cmd/mesh-build-node/build.go b/modules/mesh-build-node/cmd/mesh-build-node/build.go
index 00a966817..4c7bb7da0 100644
--- a/modules/mesh-build-node/cmd/mesh-build-node/build.go
+++ b/modules/mesh-build-node/cmd/mesh-build-node/build.go
@@ -168,7 +168,7 @@ func (m *Module) build(ctx context.Context, args map[string]any) (any, error) {
 	// Published from this process once the build ended, a candidate's as a trunk build's (ADR 0498 §1 §2; CAT-BN3): the
 	// step answers the seat's reference, or fails not stored. The packed bytes are never written to the node (L9).
 	if err := m.publishOn(ctx, buildstep.ArtifactSeat, a.module+"/"+a.Name, "bundle", "", digest, archive); err != nil {
-		return nil, fmt.Errorf("%s%s: %v", builds.NotStored, a.Name, err)
+		return nil, fmt.Errorf("%s%s: %w", builds.NotStored, a.Name, err)
 	}
 	files := []string{}
 	_ = filepath.WalkDir(bundleDir, func(p string, d os.DirEntry, err error) error {
diff --git a/modules/mesh-build-node/cmd/mesh-build-node/package.go b/modules/mesh-build-node/cmd/mesh-build-node/package.go
index bb2f51bcc..ab61e2e1b 100644
--- a/modules/mesh-build-node/cmd/mesh-build-node/package.go
+++ b/modules/mesh-build-node/cmd/mesh-build-node/package.go
@@ -551,7 +551,7 @@ func (m *Module) buildPackage(ctx context.Context, workspace, module, root, dir,
 		return res, nil
 	}
 	if err := m.publishOn(ctx, seat, p.Name, "package", p.Version, p.Digest, p.tgz); err != nil {
-		return nil, fmt.Errorf("%s%s: %v", builds.NotStored, a.Name, err)
+		return nil, fmt.Errorf("%s%s: %w", builds.NotStored, a.Name, err)
 	}
 	res.Reference = p.Name + "@" + p.Version
 	return res, nil
diff --git a/modules/mesh-build-node/cmd/mesh-build-node/push_test.go b/modules/mesh-build-node/cmd/mesh-build-node/push_test.go
index 4854a59e3..4e526e139 100644
--- a/modules/mesh-build-node/cmd/mesh-build-node/push_test.go
+++ b/modules/mesh-build-node/cmd/mesh-build-node/push_test.go
@@ -17,6 +17,7 @@ import (
 
 	"git.novox.be/novox/mesh-catalog/modules/mesh-build-go/buildstep"
 	builds "git.novox.be/novox/mesh-delivery/modules/mesh-delivery-builder/builds"
+	sdkstep "git.novox.be/novox/mesh-delivery/sdk/buildstep"
 )
 
 // pushed are the blobs the fake holder took, by digest, for the tests that read an archive back.
@@ -130,6 +131,18 @@ func TestARefusedPushFailsNotStoredAndNoPackedFileStays(t *testing.T) {
 		if c.words != "" && (err == nil || !strings.HasPrefix(err.Error(), builds.NotStored+"tools: ") || !strings.Contains(err.Error(), c.words)) {
 			t.Errorf("a refused publish answered %v", err)
 		}
+		if c.noSeat {
+			// ADR 0664 §1: with a holder named by the assigner the same words are a transport fault, the bus gives the ask again.
+			m.Call = func(key string, _ any) (json.RawMessage, error) {
+				if key == buildstep.AssignerHolders {
+					return json.RawMessage(`{"seats":[{"seat":"oci-artifact-registry","holders":[{"module":"mesh-registry","node":"novox"}]}],"holds":1}`), nil
+				}
+				return nil, errors.New("nats: no responders available for request")
+			}
+			if _, err := m.build(context.Background(), buildArgs()); err == nil || !sdkstep.IsPassing(err) || !strings.Contains(err.Error(), "the holder is silent") {
+				t.Errorf("no responders with a holder named answered %v, want a transport fault", err)
+			}
+		}
 		var archives []string
 		filepath.WalkDir(work, func(p string, d os.DirEntry, err error) error {
 			if err == nil && strings.HasSuffix(p, ".tar.gz") {
diff --git a/modules/mesh-build-node/go.mod b/modules/mesh-build-node/go.mod
index 6d3d86384..dc59b88f2 100644
--- a/modules/mesh-build-node/go.mod
+++ b/modules/mesh-build-node/go.mod
@@ -94,6 +94,7 @@ require git.novox.be/novox/mesh-catalog/modules/ssh-client/sshkeys v0.0.0-000101
 replace git.novox.be/novox/mesh-catalog/modules/ssh-client/sshkeys => ../ssh-client/sshkeys
 
 require (
+	git.novox.be/novox/mesh-contracts/go/seats/meshmoduleassigner v0.0.0-00010101000000-000000000000 // indirect
 	git.novox.be/novox/mesh-delivery/contracts/go/clients/gopackageregistryclient v0.0.0-00010101000000-000000000000 // indirect
 	git.novox.be/novox/mesh-delivery/contracts/go/clients/meshcatalogclient v0.0.0-00010101000000-000000000000 // indirect
 	git.novox.be/novox/mesh-delivery/contracts/go/clients/npmpackageregistryclient v0.0.0-00010101000000-000000000000 // indirect
diff --git a/modules/mesh-build-node/module.json b/modules/mesh-build-node/module.json
index c73dd5954..9d48c9104 100644
--- a/modules/mesh-build-node/module.json
+++ b/modules/mesh-build-node/module.json
@@ -76,7 +76,8 @@
     "seat:oci-artifact-registry.publish",
     "seat:oci-artifact-registry.publish-part",
     "seat:npm-package-registry.publish",
-    "seat:npm-package-registry.publish-part"
+    "seat:npm-package-registry.publish-part",
+    "seat:mesh-module-assigner.assignments"
   ],
   "own-secrets": {
     "broker": "${dir:state}/broker"