docker/cli · error

failed to mount blob %s to %s: %w

Error message

failed to mount blob %s to %s: %w

What it means

Error "failed to mount blob %s to %s: %w" thrown in docker/cli.

Source

Thrown at internal/registryclient/client.go:85

// MountBlob into the registry, so it can be referenced by a manifest
func (c *client) MountBlob(ctx context.Context, sourceRef reference.Canonical, targetRef reference.Named) error {
	repoEndpoint, err := newDefaultRepositoryEndpoint(targetRef, c.insecureRegistry)
	if err != nil {
		return err
	}
	repoEndpoint.actions = []string{"pull", "push"}
	repo, err := c.getRepositoryForReference(ctx, targetRef, repoEndpoint)
	if err != nil {
		return err
	}
	lu, err := repo.Blobs(ctx).Create(ctx, distributionclient.WithMountFrom(sourceRef))
	switch err.(type) {
	case distribution.ErrBlobMounted:
		logrus.Debugf("mount of blob %s succeeded", sourceRef)
		return nil
	case nil:
	default:
		return fmt.Errorf("failed to mount blob %s to %s: %w", sourceRef, targetRef, err)
	}
	_ = lu.Cancel(ctx)
	logrus.Debugf("mount of blob %s created", sourceRef)
	return ErrBlobCreated{From: sourceRef, Target: targetRef}
}

// PutManifest sends the manifest to a registry and returns the new digest
func (c *client) PutManifest(ctx context.Context, ref reference.Named, manifest distribution.Manifest) (digest.Digest, error) {
	repoEndpoint, err := newDefaultRepositoryEndpoint(ref, c.insecureRegistry)
	if err != nil {
		return "", err
	}

	repoEndpoint.actions = []string{"pull", "push"}
	repo, err := c.getRepositoryForReference(ctx, ref, repoEndpoint)
	if err != nil {
		return "", err
	}

View on GitHub (pinned to e9452d6e78)

When it happens

Trigger: Thrown at internal/registryclient/client.go:85 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of docker/cli@e9452d6e78 (2026-08-01). Data as JSON: /data/errors/0dc30a1be42e91ce.json. Report an issue: GitHub.