QAOA circuit dumped to QPY 13 raises an error when loading #14089
Description
Environment
- Qiskit version: 1.4.2, 2.0.0rc2
- Python version: 3.12.9
- Operating system: macOS 15.3.2
What is happening?
A QAOA circuit of generated by qaoa_ansatz and dumped to QPY 13 raises an error when loading as follows.
It seems to cause Qiskit/qiskit-ibm-runtime#2193
How can we reproduce the issue?
from io import BytesIO
from qiskit import QuantumCircuit, qpy
from qiskit import __version__ as qiskit_version
from qiskit.circuit import ParameterVector
from qiskit.circuit.library import QAOAAnsatz, qaoa_ansatz
from qiskit.quantum_info import SparsePauliOp
def qpy_dump_load(qc, version):
with BytesIO() as obj:
qpy.dump(qc, obj, version=version)
obj.seek(0)
qc = qpy.load(obj)[0]
return qc
print(f"{qiskit_version=}")
op = SparsePauliOp(["ZIZI", "IZIZ", "ZIIZ"])
qaoa = {"QAOAAnsatz": QAOAAnsatz(op, reps=1), "qaoa_ansatz": qaoa_ansatz(op, reps=1)}
for qpy_version in [11, 13]:
print(f"{qpy_version=}")
for name, ansatz in qaoa.items():
print(name)
x = ParameterVector("γ", 1)
ansatz = ansatz.assign_parameters({ansatz.parameters[1]: x[0]})
qc = QuantumCircuit(4)
qc.append(ansatz, range(4))
qc2 = qpy_dump_load(qc, qpy_version)
params = [0] * qc2.num_parameters
qc2.assign_parameters(params, inplace=True)
print("OK")qiskit_version='1.4.2'
qpy_version=11
QAOAAnsatz
OK
qaoa_ansatz
OK
qpy_version=13
QAOAAnsatz
OK
qaoa_ansatz
Traceback (most recent call last):
File "/Users/ima/tasks/5_2025/scripts/2025/terra/qaoa2.py", line 31, in <module>
qc2 = qpy_dump_load(qc, qpy_version)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/Users/ima/tasks/5_2025/scripts/2025/terra/qaoa2.py", line 14, in qpy_dump_load
qc = qpy.load(obj)[0]
^^^^^^^^^^^^^
File "/Users/ima/envs/qiskit/lib/python3.12/site-packages/qiskit/qpy/interface.py", line 383, in load
loader(
File "/Users/ima/envs/qiskit/lib/python3.12/site-packages/qiskit/qpy/binary_io/circuits.py", line 1449, in read_circuit
custom_operations = _read_custom_operations(file_obj, version, vectors)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/Users/ima/envs/qiskit/lib/python3.12/site-packages/qiskit/qpy/binary_io/circuits.py", line 617, in _read_custom_operations
definition_circuit = common.data_from_binary(
^^^^^^^^^^^^^^^^^^^^^^^^
File "/Users/ima/envs/qiskit/lib/python3.12/site-packages/qiskit/qpy/common.py", line 267, in data_from_binary
obj = deserializer(container, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/Users/ima/envs/qiskit/lib/python3.12/site-packages/qiskit/qpy/binary_io/circuits.py", line 1451, in read_circuit
_read_instruction(
File "/Users/ima/envs/qiskit/lib/python3.12/site-packages/qiskit/qpy/binary_io/circuits.py", line 297, in _read_instruction
param = _loads_instruction_parameter(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/Users/ima/envs/qiskit/lib/python3.12/site-packages/qiskit/qpy/binary_io/circuits.py", line 201, in _loads_instruction_parameter
param = value.loads_value(
^^^^^^^^^^^^^^^^^^
File "/Users/ima/envs/qiskit/lib/python3.12/site-packages/qiskit/qpy/binary_io/value.py", line 988, in loads_value
return common.data_from_binary(
^^^^^^^^^^^^^^^^^^^^^^^^
File "/Users/ima/envs/qiskit/lib/python3.12/site-packages/qiskit/qpy/common.py", line 267, in data_from_binary
obj = deserializer(container, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/Users/ima/envs/qiskit/lib/python3.12/site-packages/qiskit/qpy/binary_io/value.py", line 559, in _read_parameter_expression_v13
return _read_parameter_expr_v13(buf, symbol_map, version, vectors)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/Users/ima/envs/qiskit/lib/python3.12/site-packages/qiskit/qpy/binary_io/value.py", line 642, in _read_parameter_expr_v13
stack.append(getattr(lhs, method_str)(rhs))
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/Users/ima/envs/qiskit/lib/python3.12/site-packages/qiskit/circuit/parameterexpression.py", line 264, in subs
self._raise_if_passed_unknown_parameters(parameter_map.keys())
File "/Users/ima/envs/qiskit/lib/python3.12/site-packages/qiskit/circuit/parameterexpression.py", line 300, in _raise_if_passed_unknown_parameters
raise CircuitError(
qiskit.circuit.exceptions.CircuitError: "Cannot bind Parameters (['γ[0]']) not present in expression."
What should happen?
No error as same as QPY 11
Any suggestions?
No response