From 09096ea56530d2f7bcabb1b9f2ae9fd0258c0420 Mon Sep 17 00:00:00 2001
From: chenyu <chenyu@fastmail.com>
Date: Thu, 14 May 2026 19:26:47 -0400
Subject: [PATCH] test_gradient_through_clone (#16203)

backward through clone crashes now
---
 test/unit/test_gradient.py | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/test/unit/test_gradient.py b/test/unit/test_gradient.py
index 3364e6fe09..f672291c7c 100644
--- a/test/unit/test_gradient.py
+++ b/test/unit/test_gradient.py
@@ -69,6 +69,21 @@ class TestTensorGradient(unittest.TestCase):
     np.testing.assert_allclose(x.grad.numpy(), [2.0+3.0+2*3.0])
     self.assertIs(x.grad, old_grad)
 
+  def test_gradient_through_clone(self):
+    src = Tensor([1.0, 2.0, 3.0, 4.0])
+    x = src.clone().requires_grad_(True)
+    (x * 2.0).sum().backward()
+    np.testing.assert_allclose(x.grad.numpy(), [2.0, 2.0, 2.0, 2.0])
+    self.assertIsNone(src.grad)
+
+    src = Tensor([1.0, 2.0, 3.0, 4.0], requires_grad=True)
+    x = src.clone().requires_grad_(True)
+    try:
+      (x * 2.0).sum().backward()
+    except RuntimeError:
+      # TODO: this crashes now
+      pass
+
   def test_gradient_through_chained_unrealized_setitem(self):
     g1 = Tensor.zeros(4).contiguous()
     g1[2] = Tensor(1.0)