--- a/mercurial/setdiscovery.py	Mon Jan 06 01:14:52 2025 +0100
+++ b/mercurial/setdiscovery.py	Tue Jan 07 17:34:25 2025 +0100
@@ -276,7 +276,7 @@
 pure_partialdiscovery = partialdiscovery
 
 partialdiscovery = policy.importrust(
-    'discovery', member='PartialDiscovery', default=partialdiscovery
+    'discovery', member='PartialDiscovery', default=partialdiscovery, pyo3=True
 )