Fix: Handle older versions of qasm that do not implement copy

qiskit_rigetti/_qcs_backend.py

@@ -15,6 +15,7 @@
 ##############################################################################
 from typing import Optional, Any, Union, List, cast, Tuple
 from uuid import uuid4
+import copy
 
 from pyquil import get_qc
 from pyquil.api import QuantumComputer, EngagementManager
@@ -82,7 +83,10 @@ def _prepare_circuit(circuit: QuantumCircuit) -> QuantumCircuit:
     """
     Returns a prepared copy of the circuit for execution on the QCS Backend.
     """
-    circuit = circuit.copy()
+    if hasattr(circuit, "copy"):
+        circuit = circuit.copy()
+    else:
+        circuit = copy.deepcopy(circuit)
     _prepare_readouts(circuit)
     return circuit
 

tests/test_qcs_backend.py

@@ -162,13 +162,13 @@ def test_run__no_measurments(backend: RigettiQCSBackend):
 def test_run__backend_coupling_map():
     backend = RigettiQCSProvider().get_simulator(num_qubits=3)
     assert backend.configuration().coupling_map
-    assert [(0, 1), (0, 2), (1, 0), (1, 2), (2, 0), (2, 1)] == sorted(backend.configuration().coupling_map)
+    assert [(0, 1), (0, 2), (1, 0), (1, 2), (2, 0), (2, 1)] == sorted(list(backend.configuration().coupling_map))
 
 
 def test_run__backend_coupling_map():
     backend = RigettiQCSProvider().get_simulator(num_qubits=3)
     assert backend.configuration().coupling_map
-    assert [(0, 1), (0, 2), (1, 0), (1, 2), (2, 0), (2, 1)] == sorted(backend.configuration().coupling_map)
+    assert [(0, 1), (0, 2), (1, 0), (1, 2), (2, 0), (2, 1)] == sorted(list(backend.configuration().coupling_map))
 
 
 @pytest.fixture

tests/test_qcs_provider.py

@@ -56,7 +56,7 @@ def test_run__backend_coupling_map():
         ("http://127.0.0.1:9999/qvm",),
     ],
 )
-def test_get_simulator__remote(monkeypatch, qvm_url):
+def test_get_simulator__remote(qvm_url, monkeypatch):
     monkeypatch.setenv("QCS_SETTINGS_APPLICATIONS_PYQUIL_QVM_URL", qvm_url)
 
     with pytest.raises(GetQuantumProcessorException):