Add referral to forum in error messages

CHANGELOG.md

@@ -8,6 +8,7 @@
   into PennyLane is updated to allow passing parameters as args or kwargs, rather than as 
   a dictionary. The old dictionary UI continues to be supported.
   [(#406)](https://github.com/PennyLaneAI/pennylane-qiskit/pull/406)
+  [(#428)](https://github.com/PennyLaneAI/pennylane-qiskit/pull/428)
 
 * Measurement operations are now added to the PennyLane template when a `QuantumCircuit`
   is converted using `load`. Additionally, one can override any existing terminal

pennylane_qiskit/converter.py

@@ -35,6 +35,11 @@
 
 dagger_map = {"SdgGate": qml.S, "TdgGate": qml.T, "SXdgGate": qml.SX}
 
+referral_to_forum = (
+    "\n \nIf you are experiencing any difficulties with converting circuits from Qiskit, you can reach out "
+    "\non the PennyLane forum at https://discuss.pennylane.ai/c/pennylane-plugins/pennylane-qiskit/"
+)
+
 
 def _check_parameter_bound(param: Parameter, unbound_params: Dict[Parameter, Any]):
     """Utility function determining if a certain parameter in a QuantumCircuit has
@@ -121,7 +126,7 @@ def _format_params_dict(quantum_circuit, params, *args, **kwargs):
         # the key needs to be the actual Parameter, whereas kwargs keys are parameter names
         if not k in expected_params:
             raise TypeError(
-                f"Got unexpected parameter keyword argument '{k}'. Circuit contains parameters: {param_name_string}"
+                f"Got unexpected parameter keyword argument '{k}'. Circuit contains parameters: {param_name_string} {referral_to_forum}"
             )
         params[expected_params[k]] = v
 
@@ -140,7 +145,7 @@ def _format_params_dict(quantum_circuit, params, *args, **kwargs):
             else ""
         )
         raise TypeError(
-            f"Expected {len(expected_arg_params)} positional argument{'s' if len(expected_arg_params) > 1 else ''} but {len(args)} were given. {param_vector_info}"
+            f"Expected {len(expected_arg_params)} positional argument{'s' if len(expected_arg_params) > 1 else ''} but {len(args)} were given. {param_vector_info} {referral_to_forum}"
         )
     params.update(dict(zip(expected_arg_params, args)))
 
@@ -193,7 +198,7 @@ def _check_circuit_and_assign_parameters(
         if name in [p.name for p in quantum_circuit.parameters]:
             raise RuntimeError(
                 f"Cannot interpret QuantumCircuit with parameter '{name}' as a PennyLane "
-                f"quantum function, as this argument is reserved"
+                f"quantum function, as this argument is reserved. {referral_to_forum}"
             )
 
     expected_params, param_name_string = _expected_parameters(quantum_circuit)
@@ -202,7 +207,7 @@ def _check_circuit_and_assign_parameters(
         if quantum_circuit.parameters:
             s = "s" if len(quantum_circuit.parameters) > 1 else ""
             raise TypeError(
-                f"Missing required argument{s} to define Parameter value{s} for: {param_name_string}"
+                f"Missing required argument{s} to define Parameter value{s} for: {param_name_string} {referral_to_forum}"
             )
         return quantum_circuit
 
@@ -212,7 +217,7 @@ def _check_circuit_and_assign_parameters(
         s = "s" if len(undefined_params) > 1 else ""
         param_names = ", ".join(undefined_params)
         raise TypeError(
-            f"Missing {len(undefined_params)} required argument{s} to define Parameter value{s} for: {param_names}"
+            f"Missing {len(undefined_params)} required argument{s} to define Parameter value{s} for: {param_names}. {referral_to_forum}"
         )
 
     for k in diff_params:

tests/test_converter.py

@@ -807,7 +807,6 @@ def test_format_params_dict_new_interface(self, args, kwargs):
         assert params == {a: 0.5, b: 0.3, c: 0.4}
 
 
-
 class TestConverterWarningsAndErrors:
     """Tests that the converter.load function emits warnings and errors."""
 
@@ -908,7 +907,6 @@ def test_too_many_args(self):
         with pytest.raises(TypeError, match="Expected 1 positional argument but 2 were given"):
             load(qc)([0.1, 0.3], 0.5, a=0.2, b=0.4)
 
-
     def test_missing_argument(self):
         """Test that if calling with missing arguments, a clear error is raised"""