@@ -473,7 +473,8 @@ func loadSpecialImage(c *testing.T, imageFunc specialimage.SpecialImageFunc) str

 	imgDir := filepath.Join(tmpDir, "image")

 	assert.NilError(c, os.Mkdir(imgDir, 0o755))

-	assert.NilError(c, imageFunc(imgDir))

+	_, err := imageFunc(imgDir)

+	assert.NilError(c, err)

 	rc, err := archive.TarWithOptions(imgDir, &archive.TarOptions{})

 	assert.NilError(c, err)

@@ -4,6 +4,8 @@ import (

 	"os"

 	"path/filepath"

 	"strings"

+

+	ocispec "github.com/opencontainers/image-spec/specs-go/v1"

 )

 const danglingImageManifestDigest = "sha256:16d365089e5c10e1673ee82ab5bba38ade9b763296ad918bd24b42a1156c5456" // #nosec G101 -- ignoring: Potential hardcoded credentials (gosec)

@@ -12,30 +14,30 @@ const danglingImageConfigDigest = "sha256:0df1207206e5288f4a989a2f13d1f5b3c4e704

 // Dangling creates an image with no layers and no tag.

 // It also has an extra org.mobyproject.test.specialimage=1 label set.

 // Layout: OCI.

-func Dangling(dir string) error {

+func Dangling(dir string) (*ocispec.Index, error) {

 	if err := os.WriteFile(filepath.Join(dir, "index.json"), []byte(`{"schemaVersion":2,"manifests":[{"mediaType":"application/vnd.docker.distribution.manifest.v2+json","digest":"sha256:16d365089e5c10e1673ee82ab5bba38ade9b763296ad918bd24b42a1156c5456","size":264,"annotations":{"org.opencontainers.image.created":"2023-05-19T08:00:44Z"},"platform":{"architecture":"amd64","os":"linux"}}]}`), 0o644); err != nil {

-		return err

+		return nil, err

 	}

 	if err := os.WriteFile(filepath.Join(dir, "manifest.json"), []byte(`[{"Config":"blobs/sha256/0df1207206e5288f4a989a2f13d1f5b3c4e70467702c1d5d21dfc9f002b7bd43","RepoTags":null,"Layers":null}]`), 0o644); err != nil {

-		return err

+		return nil, err

 	}

 	if err := os.Mkdir(filepath.Join(dir, "blobs"), 0o755); err != nil {

-		return err

+		return nil, err

 	}

 	blobsDir := filepath.Join(dir, "blobs", "sha256")

 	if err := os.Mkdir(blobsDir, 0o755); err != nil {

-		return err

+		return nil, err

 	}

 	if err := os.WriteFile(filepath.Join(blobsDir, strings.TrimPrefix(danglingImageManifestDigest, "sha256:")), []byte(`{"schemaVersion":2,"mediaType":"application/vnd.docker.distribution.manifest.v2+json","config":{"mediaType":"application/vnd.docker.container.image.v1+json","digest":"sha256:0df1207206e5288f4a989a2f13d1f5b3c4e70467702c1d5d21dfc9f002b7bd43","size":390},"layers":[]}`), 0o644); err != nil {

-		return err

+		return nil, err

 	}

 	if err := os.WriteFile(filepath.Join(blobsDir, strings.TrimPrefix(danglingImageConfigDigest, "sha256:")), []byte(`{"architecture":"amd64","config":{"Env":["PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"],"WorkingDir":"/","Labels":{"org.mobyproject.test.specialimage":"1"},"OnBuild":null},"created":null,"history":[{"created_by":"LABEL org.mobyproject.test.specialimage=1","comment":"buildkit.dockerfile.v0","empty_layer":true}],"os":"linux","rootfs":{"type":"layers","diff_ids":null}}`), 0o644); err != nil {

-		return err

+		return nil, err

 	}

-	return nil

+	return nil, nil

 }

@@ -4,53 +4,55 @@ import (

 	"io"

 	"os"

 	"path/filepath"

+

+	ocispec "github.com/opencontainers/image-spec/specs-go/v1"

 )

 // EmptyFS builds an image with an empty rootfs.

 // Layout: Legacy Docker Archive

 // See https://github.com/docker/docker/pull/5262

 // and also https://github.com/docker/docker/issues/4242

-func EmptyFS(dir string) error {

+func EmptyFS(dir string) (*ocispec.Index, error) {

 	if err := os.WriteFile(filepath.Join(dir, "manifest.json"), []byte(`[{"Config":"11f64303f0f7ffdc71f001788132bca5346831939a956e3e975c93267d89a16d.json","RepoTags":["emptyfs:latest"],"Layers":["511136ea3c5a64f264b78b5433614aec563103b4d4702f3ba7d4d2698e22c158/layer.tar"]}]`), 0o644); err != nil {

-		return err

+		return nil, err

 	}

 	if err := os.Mkdir(filepath.Join(dir, "blobs"), 0o755); err != nil {

-		return err

+		return nil, err

 	}

 	blobsDir := filepath.Join(dir, "511136ea3c5a64f264b78b5433614aec563103b4d4702f3ba7d4d2698e22c158")

 	if err := os.Mkdir(blobsDir, 0o755); err != nil {

-		return err

+		return nil, err

 	}

 	if err := os.WriteFile(filepath.Join(dir, "VERSION"), []byte(`1.0`), 0o644); err != nil {

-		return err

+		return nil, err

 	}

 	if err := os.WriteFile(filepath.Join(dir, "repositories"), []byte(`{"emptyfs":{"latest":"511136ea3c5a64f264b78b5433614aec563103b4d4702f3ba7d4d2698e22c158"}}`), 0o644); err != nil {

-		return err

+		return nil, err

 	}

 	if err := os.WriteFile(filepath.Join(dir, "11f64303f0f7ffdc71f001788132bca5346831939a956e3e975c93267d89a16d.json"), []byte(`{"architecture":"x86_64","comment":"Imported from -","container_config":{"Hostname":"","Domainname":"","User":"","AttachStdin":false,"AttachStdout":false,"AttachStderr":false,"Tty":false,"OpenStdin":false,"StdinOnce":false,"Env":null,"Cmd":null,"Image":"","Volumes":null,"WorkingDir":"","Entrypoint":null,"OnBuild":null,"Labels":null},"created":"2013-06-13T14:03:50.821769-07:00","docker_version":"0.4.0","history":[{"created":"2013-06-13T14:03:50.821769-07:00","comment":"Imported from -"}],"rootfs":{"type":"layers","diff_ids":["sha256:84ff92691f909a05b224e1c56abb4864f01b4f8e3c854e4bb4c7baf1d3f6d652"]}}`), 0o644); err != nil {

-		return err

+		return nil, err

 	}

 	if err := os.WriteFile(filepath.Join(blobsDir, "json"), []byte(`{"id":"511136ea3c5a64f264b78b5433614aec563103b4d4702f3ba7d4d2698e22c158","comment":"Imported from -","created":"2013-06-13T14:03:50.821769-07:00","container_config":{"Hostname":"","Domainname":"","User":"","Memory":0,"MemorySwap":0,"CpuShares":0,"AttachStdin":false,"AttachStdout":false,"AttachStderr":false,"PortSpecs":null,"ExposedPorts":null,"Tty":false,"OpenStdin":false,"StdinOnce":false,"Env":null,"Cmd":null,"Image":"","Volumes":null,"WorkingDir":"","Entrypoint":null,"NetworkDisabled":false,"OnBuild":null},"docker_version":"0.4.0","architecture":"x86_64","Size":0}`+"\n"), 0o644); err != nil {

-		return err

+		return nil, err

 	}

 	layerFile, err := os.OpenFile(filepath.Join(blobsDir, "layer.tar"), os.O_CREATE|os.O_WRONLY, 0o644)

 	if err != nil {

-		return err

+		return nil, err

 	}

 	defer layerFile.Close()

 	// 10240 NUL bytes is a valid empty tar archive.

 	_, err = io.Copy(layerFile, io.LimitReader(zeroReader{}, 10240))

 	if err != nil {

-		return err

+		return nil, err

 	}

-	return nil

+	return nil, nil

 }

 type zeroReader struct{}

@@ -12,15 +12,16 @@ import (

 	"github.com/docker/docker/client"

 	"github.com/docker/docker/pkg/archive"

 	"github.com/docker/docker/pkg/jsonmessage"

+	ocispec "github.com/opencontainers/image-spec/specs-go/v1"

 	"gotest.tools/v3/assert"

 )

-type SpecialImageFunc func(string) error

+type SpecialImageFunc func(string) (*ocispec.Index, error)

 func Load(ctx context.Context, t *testing.T, apiClient client.APIClient, imageFunc SpecialImageFunc) string {

 	tempDir := t.TempDir()

-	err := imageFunc(tempDir)

+	_, err := imageFunc(tempDir)

 	assert.NilError(t, err)

 	rc, err := archive.TarWithOptions(tempDir, &archive.TarOptions{})

@@ -16,20 +16,20 @@ import (

 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"

 )

-func MultiLayer(dir string) error {

+func MultiLayer(dir string) (*ocispec.Index, error) {

 	const imageRef = "multilayer:latest"

 	layer1Desc, err := writeLayerWithOneFile(dir, "foo", []byte("1"))

 	if err != nil {

-		return err

+		return nil, err

 	}

 	layer2Desc, err := writeLayerWithOneFile(dir, "bar", []byte("2"))

 	if err != nil {

-		return err

+		return nil, err

 	}

 	layer3Desc, err := writeLayerWithOneFile(dir, "hello", []byte("world"))

 	if err != nil {

-		return err

+		return nil, err

 	}

 	configDesc, err := writeJsonBlob(dir, ocispec.MediaTypeImageConfig, ocispec.Image{

@@ -43,7 +43,7 @@ func MultiLayer(dir string) error {

 		},

 	})

 	if err != nil {

-		return err

+		return nil, err

 	}

 	manifest := ocispec.Manifest{

@@ -53,7 +53,7 @@ func MultiLayer(dir string) error {

 	}

 	legacyManifests := []manifestItem{

-		manifestItem{

+		{

 			Config:   blobPath(configDesc),

 			RepoTags: []string{imageRef},

 			Layers:   []string{blobPath(layer1Desc), blobPath(layer2Desc), blobPath(layer3Desc)},

@@ -62,7 +62,7 @@ func MultiLayer(dir string) error {

 	ref, err := reference.ParseNormalizedNamed(imageRef)

 	if err != nil {

-		return err

+		return nil, err

 	}

 	return singlePlatformImage(dir, ref, manifest, legacyManifests)

 }

@@ -74,10 +74,10 @@ type manifestItem struct {

 	Layers   []string

 }

-func singlePlatformImage(dir string, ref reference.Named, manifest ocispec.Manifest, legacyManifests []manifestItem) error {

+func singlePlatformImage(dir string, ref reference.Named, manifest ocispec.Manifest, legacyManifests []manifestItem) (*ocispec.Index, error) {

 	manifestDesc, err := writeJsonBlob(dir, ocispec.MediaTypeImageManifest, manifest)

 	if err != nil {

-		return err

+		return nil, err

 	}

 	if ref != nil {

@@ -90,25 +90,24 @@ func singlePlatformImage(dir string, ref reference.Named, manifest ocispec.Manif

 		}

 	}

-	if err := writeJson(ocispec.Index{

+	idx := ocispec.Index{

 		Versioned: specs.Versioned{SchemaVersion: 2},

 		MediaType: ocispec.MediaTypeImageIndex,

 		Manifests: []ocispec.Descriptor{manifestDesc},

-	}, filepath.Join(dir, "index.json")); err != nil {

-		return err

 	}

-	if err != nil {

-		return err

+	if err := writeJson(idx, filepath.Join(dir, "index.json")); err != nil {

+		return nil, err

 	}

-

 	if err := writeJson(legacyManifests, filepath.Join(dir, "manifest.json")); err != nil {

-		return err

+		return nil, err

 	}

+

+	err = os.WriteFile(filepath.Join(dir, "oci-layout"), []byte(`{"imageLayoutVersion": "1.0.0"}`), 0o644)

 	if err != nil {

-		return err

+		return nil, err

 	}

-	return os.WriteFile(filepath.Join(dir, "oci-layout"), []byte(`{"imageLayoutVersion": "1.0.0"}`), 0o644)

+	return &idx, nil

 }

 func fileArchive(dir string, name string, content []byte) (io.ReadCloser, error) {