Add copy_libuv_to_torch_lib so we shm.dll can find libuv at runtime

harkgill-amd · harkgill-amd · commit 2c48fe46cb29 · 2026-06-04T14:18:02.000-04:00
diff --git a/external-builds/pytorch/build_prod_wheels.py b/external-builds/pytorch/build_prod_wheels.py
@@ -925,6 +925,18 @@ def copy_msvc_libomp_to_torch_lib(pytorch_dir: Path):
     shutil.copy2(omp_path, target_lib)
 
 
+def copy_libuv_to_torch_lib(pytorch_dir: Path):
+    libuv_root = os.environ.get("libuv_ROOT", "")
+    if not libuv_root:
+        return
+    uv_dll = Path(libuv_root) / "bin" / "uv.dll"
+    if not uv_dll.exists():
+        raise RuntimeError(f"Did not find uv.dll at '{uv_dll}'")
+    target_lib = pytorch_dir / "torch" / "lib"
+    print(f"Copying libuv from '{uv_dll}' to '{target_lib}'")
+    shutil.copy2(uv_dll, target_lib)
+
+
 def do_build_pytorch(
     args: argparse.Namespace,
     pytorch_dir: Path,
@@ -1054,6 +1066,7 @@ def do_build_pytorch(
     # Windows-specific settings.
     if is_windows:
         copy_msvc_libomp_to_torch_lib(pytorch_dir)
+        copy_libuv_to_torch_lib(pytorch_dir)
 
         use_flash_attention = (
             "1"
