Allow an abstract .mv value without wires

pennylane/measurements/measurements.py

@@ -23,6 +23,7 @@
 from typing import Optional, Sequence, Tuple, Union
 
 import pennylane as qml
+from pennylane.math.utils import is_abstract
 from pennylane.operation import DecompositionUndefinedError, EigvalsUndefinedError, Operator
 from pennylane.pytrees import register_pytree
 from pennylane.typing import TensorLike
@@ -162,6 +163,9 @@ def __init__(
  # Cast sequence of measurement values to list
  self.mv = obs if getattr(obs, "name", None) == "MeasurementValue" else list(obs)
  self.obs = None
+ elif is_abstract(obs): # Catalyst program with qml.sample(m, wires=i)
+ self.mv = obs
+ self.obs = None
  else:
  self.obs = obs
  self.mv = None
@@ -306,7 +310,7 @@ def wires(self):
 
  This is the union of all the Wires objects of the measurement.
  """
- if self.mv is not None:
+ if self.mv is not None and not is_abstract(self.mv):
  if isinstance(self.mv, list):
  return qml.wires.Wires.all_wires([m.wires for m in self.mv])
  return self.mv.wires