{"record":{"id":"1e0e7725f4e6c68e","repo":"jax-ml/jax","slug":"could-not-deserialize-pytreedefproto","errorCode":null,"errorMessage":"Could not deserialize PyTreeDefProto.","messagePattern":"Could not deserialize PyTreeDefProto\\.","errorType":"exception","errorClass":"XlaRuntimeError","httpStatus":null,"severity":"error","filePath":"jaxlib/pytree.cc","lineNumber":1887,"sourceCode":"    return AbslHashToPythonHash(absl::HashOf(t));\n  });\n  treedef.def(\"serialize_using_proto\", [](const PyTreeDef& a) {\n    PyTreeDefProto result;\n    a.SerializeTo(result);\n    std::string serialized = result.SerializeAsString();\n    return nb::bytes(serialized.data(), serialized.size());\n  });\n  treedef.def_static(\n      \"deserialize_using_proto\",\n      [](nb_class_ptr<PyTreeRegistry> registry, nb::bytes data) {\n        PyTreeDefProto input;\n        std::string_view serialized(data.c_str(), data.size());\n        if (serialized.size() > std::numeric_limits<int>::max()) {\n          throw xla::XlaRuntimeError(\n              \"Pytree serialization too large to deserialize.\");\n        }\n        if (!input.ParseFromArray(serialized.data(), serialized.size())) {\n          throw xla::XlaRuntimeError(\"Could not deserialize PyTreeDefProto.\");\n        }\n        return PyTreeDef::DeserializeFrom(std::move(registry), input);\n      },\n      nb::arg(\"registry\"), nb::arg(\"data\"));\n  treedef.def(\"node_data\", &PyTreeDef::GetNodeData,\n              \"Returns None if a leaf-pytree, else (type, node_data)\",\n              nb::sig(\"def node_data(self) -> tuple[type, Any] | None\"));\n  treedef.def_static(\n      \"from_node_data_and_children\", &PyTreeDef::FromNodeDataAndChildren,\n      nb::arg(\"registry\"), nb::arg(\"node_data\").none(), nb::arg(\"children\"),\n      \"Reconstructs a pytree from `node_data()` and `children()`.\",\n      nb::sig(\n          // clang-format off\n        \"def from_node_data_and_children(\"\n        \"self, \"\n        \"registry: PyTreeRegistry, \"\n        \"node_data: tuple[type, Any] | None, \"\n        \"children: typing.Iterable[PyTreeDef]\"","sourceCodeStart":1869,"sourceCodeEnd":1905,"githubUrl":"https://github.com/jax-ml/jax/blob/1e1c6a8fc06dfcd1247076ec5cae4640cea5d7bb/jaxlib/pytree.cc#L1869-L1905","documentation":"deserialize_using_proto failed at protobuf parsing: the bytes are not a valid PyTreeDefProto encoding. This is a parse-level failure distinct from semantic validation errors like 'invalid node type'.","triggerScenarios":"Calling PyTreeDef.deserialize_using_proto(registry, data) where data is truncated, corrupted, not proto-encoded, or encoded with an incompatible proto schema.","commonSituations":"Passing JSON/pickle/str instead of proto bytes; truncated network transfer; version mismatch between the jaxlib that serialized and the one deserializing; passing the wrong field of a (treedef, leaves) tuple.","solutions":["Confirm data came from serialize_using_proto of the same jaxlib version","Validate the bytes are non-empty and were transferred intact (checksum/length)","Match jax/jaxlib versions across producer and consumer"],"exampleFix":null,"handlingStrategy":"try-catch","validationCode":"def is_likely_proto(data: bytes) -> bool:\n    return isinstance(data, (bytes, bytearray)) and len(data) > 0","typeGuard":null,"tryCatchPattern":"try:\n    treedef = pytree.PyTreeDef.deserialize_using_proto(registry, data)\nexcept Exception as e:\n    if 'Could not deserialize PyTreeDefProto' in str(e):\n        # regenerate payload with current jaxlib and retry once\n        data = reserialize_from_source()\n        treedef = pytree.PyTreeDef.deserialize_using_proto(registry, data)\n    else:\n        raise","preventionTips":["Only pass bytes from serialize_using_proto of the same version","Verify payload integrity (length/hash) before deserializing"],"tags":["jax","pytree","protobuf","corrupt-data"],"backgroundTag":"deserialization-schema-mismatch","analyzedSha":"1e1c6a8fc06dfcd1247076ec5cae4640cea5d7bb","analyzedAt":"2026-08-27T09:53:25.647Z","schemaVersion":2},"datasetVersion":"2026-08-27T13:17:12.746Z"}