wagoodman/dive · error

not implemented

Error message

not implemented

What it means

Returned by archiveResolver.Extract (dive/image/docker/archive_resolver.go:41) with a bare 'not implemented' message. Extract is meant to export a layer's contents to disk; the docker-archive resolver never implements it, so extraction from a saved tar is unsupported in this version.

Source

Thrown at dive/image/docker/archive_resolver.go:41

	reader, err := os.Open(path)
	if err != nil {
		return nil, err
	}
	defer reader.Close()

	img, err := NewImageArchive(reader)
	if err != nil {
		return nil, err
	}
	return img.ToImage(path)
}

func (r *archiveResolver) Build(ctx context.Context, args []string) (*image.Image, error) {
	return nil, fmt.Errorf("build option not supported for docker archive resolver")
}

func (r *archiveResolver) Extract(ctx context.Context, id string, l string, p string) error {
	return fmt.Errorf("not implemented")
}

View on GitHub (pinned to d6c691947f)

Solutions

1. Extract manually: the saved tarball is a regular tar - untar it and then untar the layer tar inside (tar -xf image.tar; tar -xf <layer>.tar)
2. Or re-load and extract via the engine: docker load -i image.tar, then run dive against docker://<image> which supports Extract
3. Library callers: probe capability before calling (check for the archive resolver type or an optional interface) rather than calling blindly

Example fix

// before: assuming every resolver can extract
err := resolver.Extract(ctx, id, layerPath, dest)

// after: feature-detect first
type extractor interface{ Extract(ctx context.Context, id, l, p string) error }
if _, ok := resolver.(extractor); !ok || isArchiveResolver(resolver) {
    return fmt.Errorf("source does not support extraction; untar the archive manually")
}

// feature-detect instead of calling Extract blindly
if src == dive.SourceDockerArchive {
    return extractFromArchiveManually(tarPath, layer, dest) // plain tar extraction
}
err := resolver.Extract(ctx, id, layer, dest)

err := resolver.Extract(ctx, id, layer, dest)
if err != nil {
    if strings.Contains(err.Error(), "not implemented") {
        // graceful degradation: untar the archive yourself
        err = extractLayerWithTar(tarPath, layer, dest)
    }
    if err != nil {
        return err
    }
}

When it happens

Trigger: Any Extract() call on the resolver from NewResolverFromArchive(): CLI paths that trigger layer/file extraction with --source docker-archive, or library code that uniformly calls Extract across resolvers.

Common situations: Tooling built on dive's Resolver interface that assumes all resolvers implement the full surface; users trying to export a layer from a docker-save tarball through dive instead of tar itself.

Related errors

• build option not supported for docker archive resolver
• failed to unmarshal docker config: %w
• unable to extract from image '%s': %+v
• could not find image manifest
• could not find image config

AI-assisted analysis of wagoodman/dive@d6c691947f (2026-08-15). Data as JSON: /api/errors/283b7238b643032e. Report an issue: GitHub.