Disable specific test due to bug in trt-rtx (#4571)

Author: SandSnip3r

tests/py/dynamo/conversion/test_cumsum_aten.py

@@ -1,3 +1,5 @@
+import unittest
+
 import torch
 import torch.nn as nn
 import torch_tensorrt
@@ -75,7 +77,6 @@ def forward(self, x):
             ((2, 3), (2, 4), (2, 5), 0),
             ((2, 3), (3, 4), (4, 5), -1),
             ((1, 2, 2), (2, 2, 3), (3, 3, 3), 0),
-            ((1, 2, 2), (2, 2, 3), (3, 2, 3), -2),
             ((1, 2, 2, 3), (2, 2, 3, 4), (3, 3, 4, 5), -3),
             ((1, 2, 2, 3), (2, 2, 3, 4), (3, 3, 4, 5), -2),
         ]
@@ -98,6 +99,32 @@ def forward(self, x):
             immutable_weights=False,
         )
 
+    @unittest.skipIf(
+        torch_tensorrt.ENABLED_FEATURES.tensorrt_rtx,
+        "TRT RTX (CPU-only AoT build) cannot run ConstantBuilder, which TRT requires for loops whose trip count is a compile-time constant; occurs here because dim 1 has the same size across all profiles",
+    )
+    def test_cumsum_dynamic_shape_static_dim(self):
+        # min=(1,2,2), opt=(2,2,3), max=(3,2,3), dim=-2=1
+        # dim 1 is size 2 in all profiles, so TRT uses a constant trip limit
+        min_shape, opt_shape, max_shape, dims = (1, 2, 2), (2, 2, 3), (3, 2, 3), -2
+
+        class Cumsum(nn.Module):
+            def forward(self, x):
+                return torch.ops.aten.cumsum.default(x, dims)
+
+        inputs = [
+            torch_tensorrt.Input(
+                min_shape=min_shape,
+                opt_shape=opt_shape,
+                max_shape=max_shape,
+            ),
+        ]
+        self.run_test_with_dynamic_shape(
+            Cumsum(),
+            inputs,
+            immutable_weights=False,
+        )
+
 
 if __name__ == "__main__":
     run_tests()