Test test.python.compiler.test_transpiler.TestTranspile.test_delay_converts_expr_to_dt fails in Qiskit 2.0 #14169
Description
Environment
- Qiskit version: 2.0
- Python version: 3.13.2
- Operating system: Arch Linux
What is happening?
I maintain the qiskit packages in AUR for Arch Linux users. After updating to the recent new release 2.0, the test test.python.compiler.test_transpiler.TestTranspile.test_delay_converts_expr_to_dt failed with the following error message:
==============================
Failed 1 tests - output below:
==============================
test.python.compiler.test_transpiler.TestTranspile.test_delay_converts_expr_to_dt
---------------------------------------------------------------------------------
Captured traceback:
~~~~~~~~~~~~~~~~~~~
concurrent.futures.process._RemoteTraceback:
"""
Traceback (most recent call last):
File "/usr/lib/python3.13/multiprocessing/queues.py", line 262, in _feed
obj = _ForkingPickler.dumps(obj)
File "/usr/lib/python3.13/multiprocessing/reduction.py", line 51, in dumps
cls(buf, protocol).dump(obj)
~~~~~~~~~~~~~~~~~~~~~~~^^^^^
TypeError: cannot pickle 'qiskit._accelerate.circuit.Duration_us' object
"""
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "/build/python-qiskit/src/qiskit-2.0.0/test/python/compiler/test_transpiler.py", line 1407, in test_delay_converts_expr_to_dt
out = transpile([qc, qc], backend, seed_transpiler=42)
File "/build/python-qiskit/src/test_dir/usr/lib/python3.13/site-packages/qiskit/compiler/transpiler.py", line 291, in transpile
out_circuits = pm.run(circuits, callback=callback, num_processes=num_processes)
File "/build/python-qiskit/src/test_dir/usr/lib/python3.13/site-packages/qiskit/transpiler/passmanager.py", line 451, in run
return super().run(circuits, output_name, callback, num_processes=num_processes)
~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/build/python-qiskit/src/test_dir/usr/lib/python3.13/site-packages/qiskit/transpiler/passmanager.py", line 474, in wrapper
return meth(*meth_args, **meth_kwargs)
File "/build/python-qiskit/src/test_dir/usr/lib/python3.13/site-packages/qiskit/transpiler/passmanager.py", line 233, in run
return super().run(
~~~~~~~~~~~^
in_programs=circuits,
^^^^^^^^^^^^^^^^^^^^^
...<3 lines>...
property_set=property_set,
^^^^^^^^^^^^^^^^^^^^^^^^^^
)
^
File "/build/python-qiskit/src/test_dir/usr/lib/python3.13/site-packages/qiskit/passmanager/passmanager.py", line 258, in run
return parallel_map(
_run_workflow_in_new_process,
...<5 lines>...
num_processes=num_processes,
)
File "/build/python-qiskit/src/test_dir/usr/lib/python3.13/site-packages/qiskit/utils/parallel.py", line 316, in parallel_map
return list(executor.map(_task_wrapper, work_items))
File "/usr/lib/python3.13/concurrent/futures/process.py", line 617, in _chain_from_iterable_of_lists
for element in iterable:
^^^^^^^^
File "/usr/lib/python3.13/concurrent/futures/_base.py", line 619, in result_iterator
yield _result_or_cancel(fs.pop())
~~~~~~~~~~~~~~~~~^^^^^^^^^^
File "/usr/lib/python3.13/concurrent/futures/_base.py", line 317, in _result_or_cancel
return fut.result(timeout)
~~~~~~~~~~^^^^^^^^^
File "/usr/lib/python3.13/concurrent/futures/_base.py", line 456, in result
return self.__get_result()
~~~~~~~~~~~~~~~~~^^
File "/usr/lib/python3.13/concurrent/futures/_base.py", line 401, in __get_result
raise self._exception
File "/usr/lib/python3.13/multiprocessing/queues.py", line 262, in _feed
obj = _ForkingPickler.dumps(obj)
File "/usr/lib/python3.13/multiprocessing/reduction.py", line 51, in dumps
cls(buf, protocol).dump(obj)
~~~~~~~~~~~~~~~~~~~~~~~^^^^^
TypeError: cannot pickle 'qiskit._accelerate.circuit.Duration_us' object
I'm running the python tests as close as possible to the GitHub Actions pipeline. In particular, I run:
stestr run -d test/python -E "test_equivalence_draw"These are run in a clean chroot env with just qiskit and its dependencies installed. All tests were passing with Qiskit 1.4.2.
How can we reproduce the issue?
If you want to replicate the issue in an identical env, you can try to build the package in a docker/podman container using Arch Linux image.
What should happen?
All tests should pass
Any suggestions?
No response