From 98ccf946dd46c828f0641d7596174ac565947720 Mon Sep 17 00:00:00 2001
From: Kirill Radzikhovskyy <kirillrdy@gmail.com>
Date: Tue, 30 Dec 2025 09:18:33 +1100
Subject: [PATCH] python3Packages.funsor: fix build with recent torch

---
 pkgs/development/python-modules/funsor/default.nix | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/pkgs/development/python-modules/funsor/default.nix b/pkgs/development/python-modules/funsor/default.nix
index 5cd1266db7cd..3288521439b6 100644
--- a/pkgs/development/python-modules/funsor/default.nix
+++ b/pkgs/development/python-modules/funsor/default.nix
@@ -3,6 +3,7 @@
   buildPythonPackage,
   pythonOlder,
   fetchFromGitHub,
+  fetchpatch,
 
   # build-system
   setuptools,
@@ -43,6 +44,14 @@ buildPythonPackage rec {
     hash = "sha256-Prj1saT0yoPAP8rDE0ipBEpR3QMk4PS12VSJlxc22p8=";
   };
 
+  patches = [
+    # Compatibility with torch >= 2.5 (arg_constraints is now a property)
+    (fetchpatch {
+      url = "https://github.com/pyro-ppl/funsor/commit/c5e2a48d73cad4e98058147af4090171272a44e5.patch";
+      hash = "sha256-sTR+hbJtS0Th5sIqlvB2bReEC0wnEbnB7gAiZKiqjAQ=";
+    })
+  ];
+
   build-system = [ setuptools ];
 
   dependencies = [