fix brisbane not working with ibmq_qasm_simulator anymore

pytket/extensions/qiskit/backends/ibmq_emulator.py

@@ -89,6 +89,15 @@ def __init__(
         # Get noise model:
         self._noise_model = NoiseModel.from_backend(self._ibmq._backend)
 
+        if self._ibmq._backend_info.n_nodes > 32:
+            raise ValueError(
+                "ibmq_qasm_simulator only supports 32 qubits, \
+devices with more than 32 qubtis can't be simulated"
+            )
+
+        if OpType.ECR in self._ibmq._primitive_gates:
+            raise ValueError("ibmq_qasm_simulator does not support ECR in gateset")
+
         # cache of results keyed by job id and circuit index
         self._ibm_res_cache: Dict[Tuple[str, int], Counter] = dict()
 

tests/backend_test.py

@@ -471,10 +471,9 @@ def test_nshots_batching(brisbane_backend: IBMQBackend) -> None:
 @pytest.mark.flaky(reruns=3, reruns_delay=10)
 @pytest.mark.skipif(skip_remote_tests, reason=REASON)
 def test_nshots(
-    brisbane_emulator_backend: IBMQEmulatorBackend,
     brisbane_local_emulator_backend: IBMQLocalEmulatorBackend,
 ) -> None:
-    for b in [AerBackend(), brisbane_emulator_backend, brisbane_local_emulator_backend]:
+    for b in [AerBackend(), brisbane_local_emulator_backend]:
         circuit = Circuit(1).X(0)
         circuit.measure_all()
         n_shots = [1, 2, 3]
@@ -836,10 +835,9 @@ def test_operator_expectation_value() -> None:
 @pytest.mark.flaky(reruns=3, reruns_delay=10)
 @pytest.mark.skipif(skip_remote_tests, reason=REASON)
 def test_ibmq_emulator(
-    brisbane_emulator_backend: IBMQEmulatorBackend,
     brisbane_local_emulator_backend: IBMQLocalEmulatorBackend,
 ) -> None:
-    for b in [brisbane_emulator_backend, brisbane_local_emulator_backend]:
+    for b in [brisbane_local_emulator_backend]:
         assert b._noise_model is not None  # type: ignore
         b_ibm = b._ibmq  # type: ignore
         b_aer = AerBackend()
@@ -1147,6 +1145,7 @@ def test_cloud_stabiliser(simulator_stabilizer_backend: IBMQBackend) -> None:
 
 
 # https://github.com/CQCL/pytket-qiskit/issues/278
+# @pytest.mark.flaky(reruns=3, reruns_delay=10)
 @pytest.mark.xfail(reason="Qiskit rejecting cx")
 @pytest.mark.skipif(skip_remote_tests, reason=REASON)
 def test_cloud_stabiliser_0() -> None:
@@ -1193,11 +1192,10 @@ def test_available_devices(ibm_provider: IBMProvider) -> None:
 @pytest.mark.flaky(reruns=3, reruns_delay=10)
 @pytest.mark.skipif(skip_remote_tests, reason=REASON)
 def test_backendinfo_serialization1(
-    brisbane_emulator_backend: IBMQEmulatorBackend,
     brisbane_local_emulator_backend: IBMQLocalEmulatorBackend,
 ) -> None:
     # https://github.com/CQCL/tket/issues/192
-    for b in [brisbane_emulator_backend, brisbane_local_emulator_backend]:
+    for b in [brisbane_local_emulator_backend]:
         backend_info_json = b.backend_info.to_dict()  # type: ignore
         s = json.dumps(backend_info_json)
         backend_info_json1 = json.loads(s)
@@ -1250,11 +1248,10 @@ def test_sim_qubit_order() -> None:
 @pytest.mark.flaky(reruns=3, reruns_delay=10)
 @pytest.mark.skipif(skip_remote_tests, reason=REASON)
 def test_required_predicates(
-    brisbane_emulator_backend: IBMQEmulatorBackend,
     brisbane_local_emulator_backend: IBMQLocalEmulatorBackend,
 ) -> None:
     # https://github.com/CQCL/pytket-qiskit/issues/93
-    for b in [brisbane_emulator_backend, brisbane_local_emulator_backend]:
+    for b in [brisbane_local_emulator_backend]:
         circ = Circuit(8)  # 8 qubit circuit in IBMQ gateset
         circ.X(0).CX(0, 1).CX(0, 2).CX(0, 3).CX(0, 4).CX(0, 5).CX(0, 6).CX(
             0, 7