Environment

• Qiskit version: Qiskit 1.3.0 and main
• Python version: 3.11.9
• Operating system: macOS

What is happening?

This is the problem underlying Qiskit/qiskit-addon-cutting#714.

Running basis translation in parallel (see snippet below) causes the following failure

[...]
  File "/Users/jul/Qiskit/qiskit/qiskit/transpiler/passes/basis/basis_translator.py", line 129, in run
    return base_run(
           ^^^^^^^^^
ValueError: An invalid parameter was provided. 

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/Users/jul/IBM/snippets/repro.py", line 25, in <module>
    pm.run([qc_a, qc_b]) # This fails with the error
    ^^^^^^^^^^^^^^^^^^^^
[...]

  File "/opt/homebrew/Cellar/python@3.11/3.11.9/Frameworks/Python.framework/Versions/3.11/lib/python3.11/concurrent/futures/_base.py", line 401, in __get_result
    raise self._exception
ValueError: An invalid parameter was provided.

This seems to be due to the recent port of the basis translator to Rust (see #12246 for an overview). Dissecting the code, the error seems to be triggered by compose_transforms, so it might be worth checking if this already existed after #13137 and before the rest of the basis translator was moved to Rust.

How can we reproduce the issue?

From @mtreinish:

I just came up with a minimal reproduce:

from qiskit.circuit import QuantumCircuit, Parameter
from qiskit import generate_preset_pass_manager
from qiskit.providers.fake_provider import GenericBackendV2
from qiskit.circuit.library import RXGate

backend = GenericBackendV2(5)
pm = generate_preset_pass_manager(1, backend)

param = Parameter('a')
gate = RXGate(param)

qc_a = QuantumCircuit(1)
qc_a.append(gate, [0])
qc_b = QuantumCircuit(1)
qc_b.append(gate, [0])

pm.run(qc_a)
pm.run(qc_b)
pm.run([qc_a, qc_b]) # This fails with the error

Note that this only happens with multiprocessing turned on. On Mac this is turned off per default but can be enabled with export QISKIT_PARALLEL=TRUE.

What should happen?

The above should run, as it did in 1.2.4.

Any suggestions?

One possible solution is to delete the cached py_op upon parameter assignment, i.e. replace

previous.py_op = OnceLock::new();  // or OnceCell on Qiskit 1.3.0

But this comes at a ~5% performance overhead on my machine, benchmarked on some utility scale circuits. Maybe there's another way to avoid this overhead?