Adding Op in message when grad is not implemented

pytensor/graph/op.py

@@ -13,6 +13,7 @@
 
 import pytensor
 from pytensor.configdefaults import config
+from pytensor.gradient import grad_not_implemented
 from pytensor.graph.basic import Apply, Variable
 from pytensor.graph.utils import (
     MetaObject,
@@ -357,7 +358,14 @@ def grad(
         .. [1] Giles, Mike. 2008. “An Extended Collection of Matrix Derivative Results for Forward and Reverse Mode Automatic Differentiation.”
 
         """
-        raise NotImplementedError()
+        # raise NotImplementedError()
+        (a,) = inputs
+        a_grad = grad_not_implemented(
+            self,
+            0,
+            a,
+        )
+        return [a_grad]
 
     def L_op(
         self,