GoogleContainerTools/jib · error · LayerPropertyNotFoundException

Blob not available for reference layer

Error message

Blob not available for reference layer

What it means

ReferenceLayer is a metadata-only view of a layer (blob descriptor + diff ID) referenced from a manifest; it does not hold the layer's compressed content. getBlob() therefore throws LayerPropertyNotFoundException.

Solutions

1. Fetch the blob content from the registry (RegistryClient layer pull) using the layer digest instead of getBlob()
2. Use a CachedLayer from the layer cache when local content is needed
3. Guard with instanceof checks and only call getBlob() on layers that carry content

Example fix

// before
Blob blob = layer.getBlob();
// after
if (layer instanceof CachedLayer) {
  Blob blob = ((CachedLayer) layer).getBlob();
} else {
  DescriptorDigest digest = layer.getBlobDescriptor().getDigest();
}

boolean canGetBlob = layer instanceof CachedLayer;

boolean hasBlobContent(Layer l) { return l instanceof CachedLayer; }

try { Blob b = layer.getBlob(); } catch (LayerPropertyNotFoundException e) { pullBlobFromRegistry(layer.getBlobDescriptor().getDigest()); }

When it happens

Trigger: Calling Layer.getBlob() on a ReferenceLayer created via ReferenceLayer.of(blobDescriptor, diffId) or returned by JsonToImageTranslator.toImage.

Common situations: Pulling an image via the registry API and then trying to stream layer blobs from the in-memory Image object; migrating manifests where content was never downloaded; tests assuming getBlob() works on all layers.

Understand the failure class

Background: UnsupportedOperationException and "is not supported" errors: when a library deliberately refuses a call — this error's family across 30 libraries.

Related errors

• Blob not available for digest-only layer
• Blob not available for reference layer without diff ID
• Diff ID not available for digest-only layer
• Diff ID not available for reference layer without diff ID
• All layers in the manifest template must have digest set

AI-assisted analysis of GoogleContainerTools/jib@fb949e2676 (2026-09-06). Data as JSON: /api/errors/27bfe6d890b172ed. Report an issue: GitHub.

Appendix: source

Thrown at jib-core/src/main/java/com/google/cloud/tools/jib/image/ReferenceLayer.java:48

  private final BlobDescriptor blobDescriptor;

  /** The digest of the uncompressed layer content. */
  private final DescriptorDigest diffId;

  /**
   * Instantiate with a {@link BlobDescriptor} and diff ID.
   *
   * @param blobDescriptor the blob descriptor
   * @param diffId the diff ID
   */
  public ReferenceLayer(BlobDescriptor blobDescriptor, DescriptorDigest diffId) {
    this.blobDescriptor = blobDescriptor;
    this.diffId = diffId;
  }

  @Override
  public Blob getBlob() throws LayerPropertyNotFoundException {
    throw new LayerPropertyNotFoundException("Blob not available for reference layer");
  }

  @Override
  public BlobDescriptor getBlobDescriptor() {
    return blobDescriptor;
  }

  @Override
  public DescriptorDigest getDiffId() {
    return diffId;
  }
}

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