Check if a layer is provided in the manifest

pkg/compiler/backend/simpledocker.go

@@ -163,10 +163,13 @@ func (*SimpleDocker) ExtractRootfs(opts compiler.CompilerBackendOptions, keepPer
 	layers_sha := []string{}
 
 	for _, data := range manifestData {
+
 		for _, l := range data.Layers {
+			if strings.Contains(l, "layer.tar") {
 				layers_sha = append(layers_sha, strings.Replace(l, "/layer.tar", "", -1))
 			}
 		}
+	}
 
 	export, err := capi.CreateExport(rootfs)
 	if err != nil {