Error with circuits with multiple registers

[CorentinB78]

Qiskit circuits with several quantum registers fail at running on the simulator or on actual devices. The same circuit with just a single register or no register (default register I suppose) works without problem.

Steps to reproduce the problem

Example on the simulator. This does not work:

from qiskit import circuit
from qiskit_braket_provider import BraketLocalBackend

reg_a = circuit.QuantumRegister(1, "reg_A")
reg_b = circuit.QuantumRegister(1, "reg_B")
circ = circuit.QuantumCircuit(reg_a, reg_b)
circ.ry(1.0, 0)
circ.cx(0, 1)

device = BraketLocalBackend()

task = device.run(circ, shots=10)

while this works:

from qiskit import circuit
from qiskit_braket_provider import BraketLocalBackend

reg = circuit.QuantumRegister(2, "reg")
circ = circuit.QuantumCircuit(reg)
circ.ry(1.0, 0)
circ.cx(0, 1)

device = BraketLocalBackend()

task = device.run(circ, shots=10)

What is the current behavior?

ValueError: Operator qubit count 2 must be equal to size of target qubit set QubitSet([Qubit(0)])

What is the expected behavior?

It should work without error, or the error message should say that this is not supported.

[IceKhan13]

@CorentinB78 this should be resolved in #56.

We are working on tests for that. Meanwhile can you give it a try and report if you found something.

Thank you!