--- a/tests/test-http.t	Mon Jan 17 19:18:20 2022 +0100
+++ b/tests/test-http.t	Mon Jan 24 11:49:06 2022 +0100
@@ -59,8 +59,10 @@
 
   $ cat > $TESTTMP/removesupportedformat.py << EOF
   > from mercurial import localrepo
-  > def extsetup(ui):
-  >     localrepo.localrepository.supportedformats.remove(b'generaldelta')
+  > def reposetup(ui, repo):
+  >     local = repo.local()
+  >     if local is not None:
+  >         local.supported.remove(b'generaldelta')
   > EOF
 
   $ hg clone --config extensions.rsf=$TESTTMP/removesupportedformat.py --stream http://localhost:$HGPORT/ copy3