Prevent Model from turning on test value computations

pymc3/model.py

@@ -809,10 +809,7 @@ def __new__(cls, *args, **kwargs):
             instance._parent = kwargs.get("model")
         else:
             instance._parent = cls.get_context(error_if_none=False)
-        aesara_config = kwargs.get("aesara_config", None)
-        if aesara_config is None or "compute_test_value" not in aesara_config:
-            aesara_config = {"compute_test_value": "ignore"}
-        instance._aesara_config = aesara_config
+        instance._aesara_config = kwargs.get("aesara_config", {})
         return instance
 
     def __init__(self, name="", model=None, aesara_config=None, coords=None, check_bounds=True):
@@ -1007,7 +1004,20 @@ def independent_vars(self):
     @property
     def test_point(self):
         """Test point used to check that the model doesn't generate errors"""
-        return Point(((var, var.tag.test_value) for var in self.vars), model=self)
+        points = []
+        for var in self.free_RVs:
+            var_value = getattr(var.tag, "test_value", None)
+
+            if var_value is None:
+                try:
+                    var_value = var.eval()
+                    var.tag.test_value = var_value
+                except Exception:
+                    raise Exception(f"Couldn't generate an initial value for {var}")
+
+            points.append((getattr(var.tag, "value_var", var), var_value))
+
+        return Point(points, model=self)
 
     @property
     def disc_vars(self):
@@ -1594,11 +1604,11 @@ def make_obs_var(rv_var: TensorVariable, data: Union[np.ndarray]) -> TensorVaria
     else:
         new_size = data.shape
 
-    test_value = getattr(rv_var.tag, "test_value", None)
-
     rv_var = change_rv_size(rv_var, new_size)
 
     if aesara.config.compute_test_value != "off":
+        test_value = getattr(rv_var.tag, "test_value", None)
+
         if test_value is not None:
             # We try to reuse the old test value
             rv_var.tag.test_value = np.broadcast_to(test_value, rv_var.tag.test_value.shape)