From 63b667baaea4936f7bea59d69b0f9f2a987e5f62 Mon Sep 17 00:00:00 2001
From: Pablo Brubeck <brubeck@protonmail.com>
Date: Thu, 12 Dec 2024 00:03:40 +0000
Subject: [PATCH] make cache key from weakref.proxy

---
 tsfc/fem.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tsfc/fem.py b/tsfc/fem.py
index c66c0614ad..8845bab99d 100644
--- a/tsfc/fem.py
+++ b/tsfc/fem.py
@@ -8,6 +8,7 @@
 import gem
 import numpy
 import ufl
+import weakref
 from FIAT.orientation_utils import Orientation as FIATOrientation
 from FIAT.reference_element import UFCHexahedron, UFCSimplex, make_affine_mapping
 from FIAT.reference_element import TensorProductCell
@@ -298,7 +299,7 @@ def weight_expr(self):
         return self.quadrature_rule.weight_expression
 
     def make_basis_evaluation_key(self, finat_element, mt, entity_id):
-        domain = extract_unique_domain(mt.terminal)
+        domain = weakref.proxy(extract_unique_domain(mt.terminal))
         restriction = mt.restriction
         return (self, finat_element, mt.local_derivatives, domain, restriction, entity_id)