update interface as well in resolve_execution_config

pennylane/devices/execution_config.py

@@ -15,6 +15,7 @@
 Contains the :class:`ExecutionConfig` data class.
 """
 from dataclasses import dataclass, field
+from pprint import pformat
 from typing import Optional, Union
 
 from pennylane.math import Interface, get_canonical_interface_name
@@ -136,5 +137,8 @@ def __post_init__(self):
         elif not isinstance(self.mcm_config, MCMConfig):
             raise ValueError(f"Got invalid type {type(self.mcm_config)} for 'mcm_config'")
 
+    def __str__(self):
+        return pformat(self)
+
 
 DefaultExecutionConfig = ExecutionConfig()

pennylane/workflow/construct_execution_config.py

@@ -72,11 +72,11 @@ def circuit(x):
                     gradient_keyword_arguments={},
                     device_options={'max_workers': None,
                                     'prng_key': None,
-                                    'rng': Generator(PCG64) at 0x17CFBBA00},
-                    interface=<Interface.AUTO: 'auto'>,
+                                    'rng': Generator(PCG64) at 0x15F6BB680},
+                    interface=<Interface.NUMPY: 'numpy'>,
                     derivative_order=1,
                     mcm_config=MCMConfig(mcm_method=None, postselect_mode=None),
-                convert_to_numpy=True)
+                        convert_to_numpy=True)
     """
 
     @functools.wraps(qnode)

pennylane/workflow/resolution.py

@@ -251,6 +251,7 @@ def _resolve_execution_config(
     )
     mcm_config = _resolve_mcm_config(execution_config.mcm_config, mcm_interface, finite_shots)
 
+    updated_values["interface"] = interface
     updated_values["mcm_config"] = mcm_config
 
     execution_config = replace(execution_config, **updated_values)