Environment

• Qiskit Terra version: 0.45
• Python version: 3.9.*
• Operating system: Linux

What is happening?

When a circuit is created with integer qubit operands and a barrier is applied with those operands as a set the barrier instruction is created for a single qubit operand.

How can we reproduce the issue?

from qiskit import QuantumCircuit
qc = QuantumCircuit(2)
qc.barrier({0, 1})
print(qc.data)

gives

>>> [CircuitInstruction(operation=Instruction(name='barrier', num_qubits=1, num_clbits=0, params=[]), qubits=(Qubit(QuantumRegister(2, 'q'), 0), Qubit(QuantumRegister(2, 'q'), 1)), clbits=())]

What should happen?

I would expect (and the behaviour was this way in 0.44)

>>> [CircuitInstruction(operation=Instruction(name='barrier', num_qubits=2, num_clbits=0, params=[]), qubits=(Qubit(QuantumRegister(2, 'q'), 0), Qubit(QuantumRegister(2, 'q'), 1)), clbits=())]

Passing a list gives the expected behaviour

qc.barrier([0, 1])

Any suggestions?

No response