From 6d2700f0b723999770e445e1ff00d7a68f46d4e3 Mon Sep 17 00:00:00 2001
From: qazal <77887910+Qazalin@users.noreply.github.com>
Date: Fri, 31 Jul 2026 19:24:44 +0800
Subject: [PATCH] failing test for unbound _device_num err in BEAM (#17326)

* min failing test

* switch to cpu

* err
---
 test/backend/test_multitensor.py | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/test/backend/test_multitensor.py b/test/backend/test_multitensor.py
index ce218ac7a9..5ee6a0cc3b 100644
--- a/test/backend/test_multitensor.py
+++ b/test/backend/test_multitensor.py
@@ -76,6 +76,14 @@ class TestMultiTensor(unittest.TestCase):
     run_linear(linear)
     self.assertEqual(len(set(names)), 1, "function was relinearized")
 
+  @unittest.expectedFailure
+  def test_shard_beam(self):
+    cpu_2 = ("CPU:1", "CPU:2")
+    src = Tensor.ones(16).shard(cpu_2, 0).realize()
+    pad = src.to(cpu_2[::-1]).schedule_linear().src[0]
+    with Context(BEAM=1, IGNORE_BEAM_CACHE=1): prg = compile_linear(UOp(Ops.LINEAR, src=(pad,))).src[0].src[0]
+    self.assertNotEqual(prg.src[0].arg.applied_opts, ())
+
   def test_shard_same_device(self):
     X = Tensor.ones(256).contiguous().realize()
     X.shard_((d1, X.device), 0)