Overflow error: Seed Transpiler Validation

[glanzz]

Environment

• Qiskit version: 1.1.1
• Python version: 3.11
• Operating system: MacOS

What is happening?

The pass manager crashes when i am provided with negative seed_transpiler value to the for layout method is 'sabre' even for normal circuit.
The seed_transpiler is not validated properly.
The issue is also found when run with complex circuit with more number of two qubit gates.

How can we reproduce the issue?

from qiskit.transpiler.preset_passmanagers import generate_preset_pass_manager
from qiskit import QuantumCircuit
from qiskit_ibm_runtime.fake_provider import FakeSherbrooke
qc = QuantumCircuit(3)
qc.x(0)
qc.x(1)
qc.x(2)
qc.measure_all()

backend = FakeSherbrooke()
options = {
  'layout_method': 'sabre',
  'seed_transpiler': -1,
}

pass_manager = generate_preset_pass_manager(backend=backend, optimization_level=i, **options)
transpiled_circuit = pass_manager.run(qc)

print(backend.run(transpiled_circuit, shots=100).result().get_counts())

What should happen?

There should be an unsigned int overflowerror

Traceback (most recent call last):
  File "/Users/xxx/Projects/circuit_generator/gen_mod.py", line 36, in <module>
    transpiled_circuit = pass_manager.run(qc)
                         ^^^^^^^^^^^^^^^^^^^^
  File "/Users/xxx/Projects/circuit_generator/venv/lib/python3.11/site-packages/qiskit/transpiler/passmanager.py", line 440, in run
    return super().run(circuits, output_name, callback, num_processes=num_processes)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/xxx/Projects/circuit_generator/venv/lib/python3.11/site-packages/qiskit/transpiler/passmanager.py", line 463, in wrapper
    return meth(*meth_args, **meth_kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/xxx/Projects/circuit_generator/venv/lib/python3.11/site-packages/qiskit/transpiler/passmanager.py", line 225, in run
    return super().run(
           ^^^^^^^^^^^^
  File "/Users/xxx/Projects/circuit_generator/venv/lib/python3.11/site-packages/qiskit/passmanager/passmanager.py", line 231, in run
    out = [
          ^
  File "/Users/xxx/Projects/circuit_generator/venv/lib/python3.11/site-packages/qiskit/passmanager/passmanager.py", line 232, in <listcomp>
    _run_workflow(program=program, pass_manager=self, callback=callback, **kwargs)
  File "/Users/xxx/Projects/circuit_generator/venv/lib/python3.11/site-packages/qiskit/passmanager/passmanager.py", line 292, in _run_workflow
    passmanager_ir, final_state = flow_controller.execute(
                                  ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/xxx/Projects/circuit_generator/venv/lib/python3.11/site-packages/qiskit/passmanager/base_tasks.py", line 218, in execute
    passmanager_ir, state = next_task.execute(
                            ^^^^^^^^^^^^^^^^^^
  File "/Users/xxx/Projects/circuit_generator/venv/lib/python3.11/site-packages/qiskit/passmanager/base_tasks.py", line 218, in execute
    passmanager_ir, state = next_task.execute(
                            ^^^^^^^^^^^^^^^^^^
  File "/Users/xxx/Projects/circuit_generator/venv/lib/python3.11/site-packages/qiskit/transpiler/basepasses.py", line 195, in execute
    new_dag, state = super().execute(
                     ^^^^^^^^^^^^^^^^
  File "/Users/xxx/Projects/circuit_generator/venv/lib/python3.11/site-packages/qiskit/passmanager/base_tasks.py", line 98, in execute
    ret = self.run(passmanager_ir)
          ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/xxx/Projects/circuit_generator/venv/lib/python3.11/site-packages/qiskit/transpiler/passes/layout/sabre_layout.py", line 269, in run
    components = disjoint_utils.run_pass_over_connected_components(dag, target, inner_run)
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/xxx/Projects/circuit_generator/venv/lib/python3.11/site-packages/qiskit/transpiler/passes/layout/disjoint_utils.py", line 51, in run_pass_over_connected_components
    return [run_func(dag, cmap_components[0])]
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/xxx/Projects/circuit_generator/venv/lib/python3.11/site-packages/qiskit/transpiler/passes/layout/sabre_layout.py", line 397, in _inner_run
    (initial_layout, final_permutation, sabre_result) = sabre_layout_and_routing(
                                                        ^^^^^^^^^^^^^^^^^^^^^^^^^
OverflowError: can't convert negative int to unsigned

Any suggestions?

Validation of seed_transpiler value in generate_preset_pass_manager function

[1ucian0]

This is a very interesting and unexpected bug introduced as part of the oxidation. Probably can be fixed in python-land by abs(seed). Or, @mtreinish, should negative seeds be supported by rusted passes?

[jakelishman]

Seeds are almost universally understood as positive integers, but in reality all that should matter is that they're a random sequence of bits. numpy.random.default_rng() will crash with a very similar error if given a negative number.

I think erroring out is the better course of action here; "fixing up" human-provided seeds to make them suitably random is well-known to be very very tricky. Using something like abs(seed) means that things like transpile(qc, seed_transpiler=x) for x in range(-10, 10) will unexpectedly use the same seed for nine pairs of runs. It's safer just to error, like other libraries do, and tell the user to give a correct input.

[1ucian0]

Got it. The fix should raise a ValueError: expected non-negative integer as a seed.

[jakelishman]

Yeah, that's fine, if we think the error message needs improving.