TranspilerError: 'The parameters pass_manager conflicts with the following parameter(s): unitary_synthesis_method.'

[kevinsung]

Environment

• Qiskit Terra version: 1ae663d
• Python version: 3.9.6
• Operating system: RHEL 8.5

What is happening?

Passing pass manager to transpile without also setting unitary_synthesis_method to None gives an error.

How can we reproduce the issue?

from qiskit import QuantumCircuit, transpile
from qiskit.test.mock import FakeMumbai
from qiskit.transpiler import PassManagerConfig
from qiskit.transpiler.preset_passmanagers import level_3_pass_manager

backend = FakeMumbai()
qubits = [0]

circuit = QuantumCircuit(1)
circuit.x(0)

pass_manager_config = PassManagerConfig(initial_layout=qubits, backend_properties=backend.properties())
pass_manager = level_3_pass_manager(pass_manager_config)

transpiled = transpile(circuit, pass_manager=pass_manager)

---------------------------------------------------------------------------
TranspilerError                           Traceback (most recent call last)
Input In [3], in <module>
     12 pass_manager_config = PassManagerConfig(initial_layout=qubits, backend_properties=backend.properties())
     13 pass_manager = level_3_pass_manager(pass_manager_config)
---> 15 transpiled = transpile(circuit, pass_manager=pass_manager)

File ~/projects/qiskit-terra/qiskit/compiler/transpiler.py:264, in transpile(circuits, backend, basis_gates, inst_map, coupling_map, backend_properties, initial_layout, layout_method, routing_method, translation_method, scheduling_method, instruction_durations, dt, approximation_degree, timing_constraints, seed_transpiler, optimization_level, pass_manager, callback, output_name, unitary_synthesis_method, unitary_synthesis_plugin_config, target)
    261         return circuits[0]
    263 if pass_manager is not None:
--> 264     _check_conflicting_argument(
    265         optimization_level=optimization_level,
    266         basis_gates=basis_gates,
    267         coupling_map=coupling_map,
    268         seed_transpiler=seed_transpiler,
    269         backend_properties=backend_properties,
    270         initial_layout=initial_layout,
    271         layout_method=layout_method,
    272         routing_method=routing_method,
    273         translation_method=translation_method,
    274         approximation_degree=approximation_degree,
    275         unitary_synthesis_method=unitary_synthesis_method,
    276         backend=backend,
    277         target=target,
    278     )
    280     warnings.warn(
    281         "The parameter pass_manager in transpile is being deprecated. "
    282         "The preferred way to tranpile a circuit using a custom pass manager is"
   (...)
    285         stacklevel=2,
    286     )
    287     return pass_manager.run(circuits, output_name=output_name, callback=callback)

File ~/projects/qiskit-terra/qiskit/compiler/transpiler.py:349, in _check_conflicting_argument(**kargs)
    347 conflicting_args = [arg for arg, value in kargs.items() if value]
    348 if conflicting_args:
--> 349     raise TranspilerError(
    350         "The parameters pass_manager conflicts with the following "
    351         "parameter(s): {}.".format(", ".join(conflicting_args))
    352     )

TranspilerError: 'The parameters pass_manager conflicts with the following parameter(s): unitary_synthesis_method.'

What should happen?

Should not be forced to set unitary_synthesis_method to None.

Any suggestions?

No response

[jakelishman]

This is true, but with the pass_manager argument to transpile deprecated, probably the best solution for us is just to effect the removal of the pass_manager keyword entirely for 0.20, and skip all that code - the deprecation has been kicking around since #4060, which was a little under a year ago now (so probably Terra 0.17 or 0.18).

[mtreinish]

Closed by: #7679 which removes the pass_manager kwarg.