[EASY] Rewrite test_anomaly_aot_autograd to more reliably trigger err…

…or (pytorch#114122)

Signed-off-by: Edward Z. Yang <ezyang@meta.com>

Pull Request resolved: pytorch#114122
Approved by: https://github.com/albanD

test/dynamo/test_misc.py

@@ -6366,11 +6366,14 @@ def my_dyn_fn(x):
         torch._dynamo.optimize("eager")(my_dyn_fn)(y)
 
     def test_anomaly_aot_autograd(self):
+        def fail():
+            raise AssertionError("fail")
+
         @allow_in_graph
         def h(a):
             r = a.sum()
             # Trigger an exception in backwards
-            r.register_hook(lambda x: x + x.item())
+            r.register_hook(lambda x: fail())
             return r
 
         @torch.compile(backend="aot_eager")
@@ -6382,8 +6385,8 @@ def f(a):
         ):
             f(torch.randn(2, 2, requires_grad=True))
 
-        self.assertEqual(len(w), 1)
-        self.assertIn("forward call that caused the error", str(w[0].message))
+        # Suppress unrelated pkg_resources warnings
+        self.assertIn("forward call that caused the error", str(w[-1].message))
 
     def test_py_guards_mark_dynamic(self):
         def my_dyn_fn(a):