diff '--color=auto' -ur pytorch-2.9.0.orig/setup.py pytorch-2.9.0/setup.py
--- pytorch-2.9.0.orig/setup.py	2025-10-15 22:10:32.194995875 +0200
+++ pytorch-2.9.0/setup.py	2025-10-15 22:16:46.029341349 +0200
@@ -484,7 +484,8 @@
 
 # Constant known variables used throughout this file
 TORCH_DIR = CWD / "torch"
-TORCH_LIB_DIR = TORCH_DIR / "lib"
+cmake_build_dir = os.environ.get("CMAKE_BUILD_DIR", CWD / "build")
+TORCH_LIB_DIR = os.path.join(cmake_build_dir, "lib")
 THIRD_PARTY_DIR = CWD / "third_party"
 
 # CMAKE: full path to python library