diff --git a/integration/copy_test.go b/integration/copy_test.go
index 6d531871..320b2e8c 100644
--- a/integration/copy_test.go
+++ b/integration/copy_test.go
@@ -154,7 +154,7 @@ func (s *CopySuite) TestCopySimple(c *check.C) {
 	// docker v2s2 -> OCI image layout without image name
 	ociDest = "busybox-latest-noimage"
 	defer os.RemoveAll(ociDest)
-	assertSkopeoFails(c, ".*Error initializing destination oci:busybox-latest-noimage:: cannot save image with empty image.ref.name.*", "copy", "docker://busybox:latest", "oci:"+ociDest)
+	assertSkopeoFails(c, ".*Error initializing destination oci:busybox-latest-noimage:: cannot save image with empty reference name.*", "copy", "docker://busybox:latest", "oci:"+ociDest)
 }
 
 // Check whether dir: images in dir1 and dir2 are equal, ignoring schema1 signatures.
diff --git a/vendor/github.com/containers/image/directory/directory_dest.go b/vendor/github.com/containers/image/directory/directory_dest.go
index a3033937..a38d7d5c 100644
--- a/vendor/github.com/containers/image/directory/directory_dest.go
+++ b/vendor/github.com/containers/image/directory/directory_dest.go
@@ -139,6 +139,7 @@ func (d *dirImageDestination) PutBlob(ctx context.Context, stream io.Reader, inp
 	digester := digest.Canonical.Digester()
 	tee := io.TeeReader(stream, digester.Hash())
 
+	// TODO: This can take quite some time, and should ideally be cancellable using ctx.Done().
 	size, err := io.Copy(blobFile, tee)
 	if err != nil {
 		return types.BlobInfo{}, err
diff --git a/vendor/github.com/containers/image/docker/archive/dest.go b/vendor/github.com/containers/image/docker/archive/dest.go
index 7db778db..12bbfa74 100644
--- a/vendor/github.com/containers/image/docker/archive/dest.go
+++ b/vendor/github.com/containers/image/docker/archive/dest.go
@@ -16,7 +16,7 @@ type archiveImageDestination struct {
 	writer               io.Closer
 }
 
-func newImageDestination(ctx context.Context, ref archiveReference) (types.ImageDestination, error) {
+func newImageDestination(ref archiveReference) (types.ImageDestination, error) {
 	if ref.destinationRef == nil {
 		return nil, errors.Errorf("docker-archive: destination reference not supplied (must be of form <path>:<reference:tag>)")
 	}
diff --git a/vendor/github.com/containers/image/docker/archive/transport.go b/vendor/github.com/containers/image/docker/archive/transport.go
index baef83e9..169a2b2e 100644
--- a/vendor/github.com/containers/image/docker/archive/transport.go
+++ b/vendor/github.com/containers/image/docker/archive/transport.go
@@ -148,7 +148,7 @@ func (ref archiveReference) NewImageSource(ctx context.Context, sys *types.Syste
 // NewImageDestination returns a types.ImageDestination for this reference.
 // The caller must call .Close() on the returned ImageDestination.
 func (ref archiveReference) NewImageDestination(ctx context.Context, sys *types.SystemContext) (types.ImageDestination, error) {
-	return newImageDestination(ctx, ref)
+	return newImageDestination(ref)
 }
 
 // DeleteImage deletes the named image from the registry, if supported.
diff --git a/vendor/github.com/containers/image/docker/docker_client.go b/vendor/github.com/containers/image/docker/docker_client.go
index c5bb95c1..4a1d4214 100644
--- a/vendor/github.com/containers/image/docker/docker_client.go
+++ b/vendor/github.com/containers/image/docker/docker_client.go
@@ -171,7 +171,7 @@ func dockerCertDir(sys *types.SystemContext, hostPort string) (string, error) {
 
 // newDockerClientFromRef returns a new dockerClient instance for refHostname (a host a specified in the Docker image reference, not canonicalized to dockerRegistry)
 // “write” specifies whether the client will be used for "write" access (in particular passed to lookaside.go:toplevelFromSection)
-func newDockerClientFromRef(ctx context.Context, sys *types.SystemContext, ref dockerReference, write bool, actions string) (*dockerClient, error) {
+func newDockerClientFromRef(sys *types.SystemContext, ref dockerReference, write bool, actions string) (*dockerClient, error) {
 	registry := reference.Domain(ref.ref)
 	username, password, err := config.GetAuthentication(sys, reference.Domain(ref.ref))
 	if err != nil {
diff --git a/vendor/github.com/containers/image/docker/docker_image.go b/vendor/github.com/containers/image/docker/docker_image.go
index e6511046..7f8ad858 100644
--- a/vendor/github.com/containers/image/docker/docker_image.go
+++ b/vendor/github.com/containers/image/docker/docker_image.go
@@ -23,7 +23,7 @@ type Image struct {
 // a client to the registry hosting the given image.
 // The caller must call .Close() on the returned Image.
 func newImage(ctx context.Context, sys *types.SystemContext, ref dockerReference) (types.ImageCloser, error) {
-	s, err := newImageSource(ctx, sys, ref)
+	s, err := newImageSource(sys, ref)
 	if err != nil {
 		return nil, err
 	}
diff --git a/vendor/github.com/containers/image/docker/docker_image_dest.go b/vendor/github.com/containers/image/docker/docker_image_dest.go
index 7ef32b63..782a048c 100644
--- a/vendor/github.com/containers/image/docker/docker_image_dest.go
+++ b/vendor/github.com/containers/image/docker/docker_image_dest.go
@@ -33,8 +33,8 @@ type dockerImageDestination struct {
 }
 
 // newImageDestination creates a new ImageDestination for the specified image reference.
-func newImageDestination(ctx context.Context, sys *types.SystemContext, ref dockerReference) (types.ImageDestination, error) {
-	c, err := newDockerClientFromRef(ctx, sys, ref, true, "pull,push")
+func newImageDestination(sys *types.SystemContext, ref dockerReference) (types.ImageDestination, error) {
+	c, err := newDockerClientFromRef(sys, ref, true, "pull,push")
 	if err != nil {
 		return nil, err
 	}
diff --git a/vendor/github.com/containers/image/docker/docker_image_src.go b/vendor/github.com/containers/image/docker/docker_image_src.go
index 924f3cbb..98f6067e 100644
--- a/vendor/github.com/containers/image/docker/docker_image_src.go
+++ b/vendor/github.com/containers/image/docker/docker_image_src.go
@@ -30,8 +30,8 @@ type dockerImageSource struct {
 
 // newImageSource creates a new ImageSource for the specified image reference.
 // The caller must call .Close() on the returned ImageSource.
-func newImageSource(ctx context.Context, sys *types.SystemContext, ref dockerReference) (*dockerImageSource, error) {
-	c, err := newDockerClientFromRef(ctx, sys, ref, false, "pull")
+func newImageSource(sys *types.SystemContext, ref dockerReference) (*dockerImageSource, error) {
+	c, err := newDockerClientFromRef(sys, ref, false, "pull")
 	if err != nil {
 		return nil, err
 	}
@@ -310,7 +310,7 @@ func (s *dockerImageSource) getSignaturesFromAPIExtension(ctx context.Context, i
 
 // deleteImage deletes the named image from the registry, if supported.
 func deleteImage(ctx context.Context, sys *types.SystemContext, ref dockerReference) error {
-	c, err := newDockerClientFromRef(ctx, sys, ref, true, "push")
+	c, err := newDockerClientFromRef(sys, ref, true, "push")
 	if err != nil {
 		return err
 	}
diff --git a/vendor/github.com/containers/image/docker/docker_transport.go b/vendor/github.com/containers/image/docker/docker_transport.go
index 24a2337f..3c67efb4 100644
--- a/vendor/github.com/containers/image/docker/docker_transport.go
+++ b/vendor/github.com/containers/image/docker/docker_transport.go
@@ -135,13 +135,13 @@ func (ref dockerReference) NewImage(ctx context.Context, sys *types.SystemContex
 // NewImageSource returns a types.ImageSource for this reference.
 // The caller must call .Close() on the returned ImageSource.
 func (ref dockerReference) NewImageSource(ctx context.Context, sys *types.SystemContext) (types.ImageSource, error) {
-	return newImageSource(ctx, sys, ref)
+	return newImageSource(sys, ref)
 }
 
 // NewImageDestination returns a types.ImageDestination for this reference.
 // The caller must call .Close() on the returned ImageDestination.
 func (ref dockerReference) NewImageDestination(ctx context.Context, sys *types.SystemContext) (types.ImageDestination, error) {
-	return newImageDestination(ctx, sys, ref)
+	return newImageDestination(sys, ref)
 }
 
 // DeleteImage deletes the named image from the registry, if supported.
diff --git a/vendor/github.com/containers/image/docker/tarfile/dest.go b/vendor/github.com/containers/image/docker/tarfile/dest.go
index 223eb9f1..2bbaf432 100644
--- a/vendor/github.com/containers/image/docker/tarfile/dest.go
+++ b/vendor/github.com/containers/image/docker/tarfile/dest.go
@@ -86,6 +86,7 @@ func (d *Destination) PutBlob(ctx context.Context, stream io.Reader, inputInfo t
 
 		digester := digest.Canonical.Digester()
 		tee := io.TeeReader(stream, digester.Hash())
+		// TODO: This can take quite some time, and should ideally be cancellable using ctx.Done().
 		size, err := io.Copy(streamCopy, tee)
 		if err != nil {
 			return types.BlobInfo{}, err
@@ -352,6 +353,7 @@ func (d *Destination) sendFile(path string, expectedSize int64, stream io.Reader
 	if err := d.tar.WriteHeader(hdr); err != nil {
 		return err
 	}
+	// TODO: This can take quite some time, and should ideally be cancellable using a context.Context.
 	size, err := io.Copy(d.tar, stream)
 	if err != nil {
 		return err
diff --git a/vendor/github.com/containers/image/docker/tarfile/src.go b/vendor/github.com/containers/image/docker/tarfile/src.go
index 8c2a70de..2a0d9966 100644
--- a/vendor/github.com/containers/image/docker/tarfile/src.go
+++ b/vendor/github.com/containers/image/docker/tarfile/src.go
@@ -81,6 +81,7 @@ func NewSourceFromStream(inputStream io.Reader) (*Source, error) {
 		}
 	}()
 
+	// TODO: This can take quite some time, and should ideally be cancellable using a context.Context.
 	if _, err := io.Copy(tarCopyFile, inputStream); err != nil {
 		return nil, errors.Wrapf(err, "error copying contents to temporary file %q", tarCopyFile.Name())
 	}
diff --git a/vendor/github.com/containers/image/oci/archive/oci_dest.go b/vendor/github.com/containers/image/oci/archive/oci_dest.go
index 105742f5..432b310b 100644
--- a/vendor/github.com/containers/image/oci/archive/oci_dest.go
+++ b/vendor/github.com/containers/image/oci/archive/oci_dest.go
@@ -125,6 +125,7 @@ func tarDirectory(src, dst string) error {
 	defer outFile.Close()
 
 	// copies the contents of the directory to the tar file
+	// TODO: This can take quite some time, and should ideally be cancellable using a context.Context.
 	_, err = io.Copy(outFile, input)
 
 	return err
diff --git a/vendor/github.com/containers/image/oci/archive/oci_transport.go b/vendor/github.com/containers/image/oci/archive/oci_transport.go
index 90600dee..7c1d26ba 100644
--- a/vendor/github.com/containers/image/oci/archive/oci_transport.go
+++ b/vendor/github.com/containers/image/oci/archive/oci_transport.go
@@ -181,6 +181,7 @@ func createUntarTempDir(ref ociArchiveReference) (tempDirOCIRef, error) {
 	}
 	src := ref.resolvedFile
 	dst := tempDirRef.tempDirectory
+	// TODO: This can take quite some time, and should ideally be cancellable using a context.Context.
 	if err := archive.UntarPath(src, dst); err != nil {
 		if err := tempDirRef.deleteTempDir(); err != nil {
 			return tempDirOCIRef{}, errors.Wrapf(err, "error deleting temp directory %q", tempDirRef.tempDirectory)
diff --git a/vendor/github.com/containers/image/oci/layout/oci_dest.go b/vendor/github.com/containers/image/oci/layout/oci_dest.go
index 3a0097bb..e0761c69 100644
--- a/vendor/github.com/containers/image/oci/layout/oci_dest.go
+++ b/vendor/github.com/containers/image/oci/layout/oci_dest.go
@@ -9,13 +9,12 @@ import (
 	"path/filepath"
 	"runtime"
 
-	"github.com/pkg/errors"
-
 	"github.com/containers/image/manifest"
 	"github.com/containers/image/types"
-	"github.com/opencontainers/go-digest"
+	digest "github.com/opencontainers/go-digest"
 	imgspec "github.com/opencontainers/image-spec/specs-go"
 	imgspecv1 "github.com/opencontainers/image-spec/specs-go/v1"
+	"github.com/pkg/errors"
 )
 
 type ociImageDestination struct {
@@ -25,9 +24,9 @@ type ociImageDestination struct {
 }
 
 // newImageDestination returns an ImageDestination for writing to an existing directory.
-func newImageDestination(ctx context.Context, sys *types.SystemContext, ref ociReference) (types.ImageDestination, error) {
+func newImageDestination(sys *types.SystemContext, ref ociReference) (types.ImageDestination, error) {
 	if ref.image == "" {
-		return nil, errors.Errorf("cannot save image with empty image.ref.name")
+		return nil, errors.Errorf("cannot save image with empty reference name (syntax must be of form <transport>:<path>:<reference>)")
 	}
 
 	var index *imgspecv1.Index
@@ -125,6 +124,7 @@ func (d *ociImageDestination) PutBlob(ctx context.Context, stream io.Reader, inp
 	digester := digest.Canonical.Digester()
 	tee := io.TeeReader(stream, digester.Hash())
 
+	// TODO: This can take quite some time, and should ideally be cancellable using ctx.Done().
 	size, err := io.Copy(blobFile, tee)
 	if err != nil {
 		return types.BlobInfo{}, err
diff --git a/vendor/github.com/containers/image/oci/layout/oci_src.go b/vendor/github.com/containers/image/oci/layout/oci_src.go
index ba314bba..33115c00 100644
--- a/vendor/github.com/containers/image/oci/layout/oci_src.go
+++ b/vendor/github.com/containers/image/oci/layout/oci_src.go
@@ -24,7 +24,7 @@ type ociImageSource struct {
 }
 
 // newImageSource returns an ImageSource for reading from an existing directory.
-func newImageSource(ctx context.Context, sys *types.SystemContext, ref ociReference) (types.ImageSource, error) {
+func newImageSource(sys *types.SystemContext, ref ociReference) (types.ImageSource, error) {
 	tr := tlsclientconfig.NewTransport()
 	tr.TLSClientConfig = tlsconfig.ServerDefault()
 
diff --git a/vendor/github.com/containers/image/oci/layout/oci_transport.go b/vendor/github.com/containers/image/oci/layout/oci_transport.go
index 72b415f0..95a9def2 100644
--- a/vendor/github.com/containers/image/oci/layout/oci_transport.go
+++ b/vendor/github.com/containers/image/oci/layout/oci_transport.go
@@ -146,7 +146,7 @@ func (ref ociReference) PolicyConfigurationNamespaces() []string {
 // verify that UnparsedImage, and convert it into a real Image via image.FromUnparsedImage.
 // WARNING: This may not do the right thing for a manifest list, see image.FromSource for details.
 func (ref ociReference) NewImage(ctx context.Context, sys *types.SystemContext) (types.ImageCloser, error) {
-	src, err := newImageSource(ctx, sys, ref)
+	src, err := newImageSource(sys, ref)
 	if err != nil {
 		return nil, err
 	}
@@ -219,13 +219,13 @@ func LoadManifestDescriptor(imgRef types.ImageReference) (imgspecv1.Descriptor,
 // NewImageSource returns a types.ImageSource for this reference.
 // The caller must call .Close() on the returned ImageSource.
 func (ref ociReference) NewImageSource(ctx context.Context, sys *types.SystemContext) (types.ImageSource, error) {
-	return newImageSource(ctx, sys, ref)
+	return newImageSource(sys, ref)
 }
 
 // NewImageDestination returns a types.ImageDestination for this reference.
 // The caller must call .Close() on the returned ImageDestination.
 func (ref ociReference) NewImageDestination(ctx context.Context, sys *types.SystemContext) (types.ImageDestination, error) {
-	return newImageDestination(ctx, sys, ref)
+	return newImageDestination(sys, ref)
 }
 
 // DeleteImage deletes the named image from the registry, if supported.
diff --git a/vendor/github.com/containers/image/openshift/openshift.go b/vendor/github.com/containers/image/openshift/openshift.go
index 4db4b40f..3504d8ce 100644
--- a/vendor/github.com/containers/image/openshift/openshift.go
+++ b/vendor/github.com/containers/image/openshift/openshift.go
@@ -170,7 +170,7 @@ type openshiftImageSource struct {
 
 // newImageSource creates a new ImageSource for the specified reference.
 // The caller must call .Close() on the returned ImageSource.
-func newImageSource(ctx context.Context, sys *types.SystemContext, ref openshiftReference) (types.ImageSource, error) {
+func newImageSource(sys *types.SystemContext, ref openshiftReference) (types.ImageSource, error) {
 	client, err := newOpenshiftClient(ref)
 	if err != nil {
 		return nil, err
diff --git a/vendor/github.com/containers/image/openshift/openshift_transport.go b/vendor/github.com/containers/image/openshift/openshift_transport.go
index b8dfee66..b27867a0 100644
--- a/vendor/github.com/containers/image/openshift/openshift_transport.go
+++ b/vendor/github.com/containers/image/openshift/openshift_transport.go
@@ -132,7 +132,7 @@ func (ref openshiftReference) PolicyConfigurationNamespaces() []string {
 // verify that UnparsedImage, and convert it into a real Image via image.FromUnparsedImage.
 // WARNING: This may not do the right thing for a manifest list, see image.FromSource for details.
 func (ref openshiftReference) NewImage(ctx context.Context, sys *types.SystemContext) (types.ImageCloser, error) {
-	src, err := newImageSource(ctx, sys, ref)
+	src, err := newImageSource(sys, ref)
 	if err != nil {
 		return nil, err
 	}
@@ -142,7 +142,7 @@ func (ref openshiftReference) NewImage(ctx context.Context, sys *types.SystemCon
 // NewImageSource returns a types.ImageSource for this reference.
 // The caller must call .Close() on the returned ImageSource.
 func (ref openshiftReference) NewImageSource(ctx context.Context, sys *types.SystemContext) (types.ImageSource, error) {
-	return newImageSource(ctx, sys, ref)
+	return newImageSource(sys, ref)
 }
 
 // NewImageDestination returns a types.ImageDestination for this reference.
diff --git a/vendor/github.com/containers/image/ostree/ostree_dest.go b/vendor/github.com/containers/image/ostree/ostree_dest.go
index 395d956e..2e0d7fcf 100644
--- a/vendor/github.com/containers/image/ostree/ostree_dest.go
+++ b/vendor/github.com/containers/image/ostree/ostree_dest.go
@@ -140,6 +140,7 @@ func (d *ostreeImageDestination) PutBlob(ctx context.Context, stream io.Reader,
 	digester := digest.Canonical.Digester()
 	tee := io.TeeReader(stream, digester.Hash())
 
+	// TODO: This can take quite some time, and should ideally be cancellable using ctx.Done().
 	size, err := io.Copy(blobFile, tee)
 	if err != nil {
 		return types.BlobInfo{}, err
@@ -264,6 +265,8 @@ func generateTarSplitMetadata(output *bytes.Buffer, file string) (digest.Digest,
 }
 
 func (d *ostreeImageDestination) importBlob(selinuxHnd *C.struct_selabel_handle, repo *otbuiltin.Repo, blob *blobToImport) error {
+	// TODO: This can take quite some time, and should ideally be cancellable using a context.Context.
+
 	ostreeBranch := fmt.Sprintf("ociimage/%s", blob.Digest.Hex())
 	destinationPath := filepath.Join(d.tmpDirPath, blob.Digest.Hex(), "root")
 	if err := ensureDirectoryExists(destinationPath); err != nil {
diff --git a/vendor/github.com/containers/image/ostree/ostree_src.go b/vendor/github.com/containers/image/ostree/ostree_src.go
index 17666951..1f325b2a 100644
--- a/vendor/github.com/containers/image/ostree/ostree_src.go
+++ b/vendor/github.com/containers/image/ostree/ostree_src.go
@@ -42,7 +42,7 @@ type ostreeImageSource struct {
 }
 
 // newImageSource returns an ImageSource for reading from an existing directory.
-func newImageSource(ctx context.Context, tmpDir string, ref ostreeReference) (types.ImageSource, error) {
+func newImageSource(tmpDir string, ref ostreeReference) (types.ImageSource, error) {
 	return &ostreeImageSource{ref: ref, tmpDir: tmpDir, compressed: nil}, nil
 }
 
diff --git a/vendor/github.com/containers/image/ostree/ostree_transport.go b/vendor/github.com/containers/image/ostree/ostree_transport.go
index 5d5dd7ab..c9856530 100644
--- a/vendor/github.com/containers/image/ostree/ostree_transport.go
+++ b/vendor/github.com/containers/image/ostree/ostree_transport.go
@@ -189,7 +189,7 @@ func (ref ostreeReference) NewImage(ctx context.Context, sys *types.SystemContex
 	} else {
 		tmpDir = sys.OSTreeTmpDirPath
 	}
-	src, err := newImageSource(ctx, tmpDir, ref)
+	src, err := newImageSource(tmpDir, ref)
 	if err != nil {
 		return nil, err
 	}
@@ -205,7 +205,7 @@ func (ref ostreeReference) NewImageSource(ctx context.Context, sys *types.System
 	} else {
 		tmpDir = sys.OSTreeTmpDirPath
 	}
-	return newImageSource(ctx, tmpDir, ref)
+	return newImageSource(tmpDir, ref)
 }
 
 // NewImageDestination returns a types.ImageDestination for this reference.
diff --git a/vendor/github.com/containers/image/storage/storage_image.go b/vendor/github.com/containers/image/storage/storage_image.go
index d4856101..e6e75945 100644
--- a/vendor/github.com/containers/image/storage/storage_image.go
+++ b/vendor/github.com/containers/image/storage/storage_image.go
@@ -239,7 +239,7 @@ func (s *storageImageSource) GetSignatures(ctx context.Context, instanceDigest *
 
 // newImageDestination sets us up to write a new image, caching blobs in a temporary directory until
 // it's time to Commit() the image
-func newImageDestination(ctx context.Context, imageRef storageReference) (*storageImageDestination, error) {
+func newImageDestination(imageRef storageReference) (*storageImageDestination, error) {
 	directory, err := ioutil.TempDir(temporaryDirectoryForBigFiles, "storage")
 	if err != nil {
 		return nil, errors.Wrapf(err, "error creating a temporary directory")
@@ -309,6 +309,7 @@ func (s *storageImageDestination) PutBlob(ctx context.Context, stream io.Reader,
 		return errorBlobInfo, errors.Wrap(err, "error setting up to decompress blob")
 	}
 	// Copy the data to the file.
+	// TODO: This can take quite some time, and should ideally be cancellable using ctx.Done().
 	_, err = io.Copy(diffID.Hash(), decompressed)
 	decompressed.Close()
 	if err != nil {
@@ -544,6 +545,7 @@ func (s *storageImageDestination) Commit(ctx context.Context) error {
 			return errors.Errorf("error applying blob %q: content not found", blob.Digest)
 		}
 		// Build the new layer using the diff, regardless of where it came from.
+		// TODO: This can take quite some time, and should ideally be cancellable using ctx.Done().
 		layer, _, err := s.imageRef.transport.store.PutLayer(id, lastLayer, nil, "", false, nil, diff)
 		if err != nil {
 			return errors.Wrapf(err, "error adding layer with blob %q", blob.Digest)
diff --git a/vendor/github.com/containers/image/storage/storage_reference.go b/vendor/github.com/containers/image/storage/storage_reference.go
index aafcecaf..53271694 100644
--- a/vendor/github.com/containers/image/storage/storage_reference.go
+++ b/vendor/github.com/containers/image/storage/storage_reference.go
@@ -206,5 +206,5 @@ func (s storageReference) NewImageSource(ctx context.Context, sys *types.SystemC
 }
 
 func (s storageReference) NewImageDestination(ctx context.Context, sys *types.SystemContext) (types.ImageDestination, error) {
-	return newImageDestination(ctx, s)
+	return newImageDestination(s)
 }
diff --git a/vendor/github.com/containers/image/tarball/tarball_src.go b/vendor/github.com/containers/image/tarball/tarball_src.go
index 4fa5eb94..17af60b3 100644
--- a/vendor/github.com/containers/image/tarball/tarball_src.go
+++ b/vendor/github.com/containers/image/tarball/tarball_src.go
@@ -87,6 +87,7 @@ func (r *tarballReference) NewImageSource(ctx context.Context, sys *types.System
 			layerType = imgspecv1.MediaTypeImageLayer
 			uncompressed = nil
 		}
+		// TODO: This can take quite some time, and should ideally be cancellable using ctx.Done().
 		n, err := io.Copy(ioutil.Discard, reader)
 		if err != nil {
 			return nil, fmt.Errorf("error reading %q: %v", filename, err)