From 032b852bab1babd3cfd3cb9acc975560d74f7315 Mon Sep 17 00:00:00 2001
From: meejah <meejah@meejah.ca>
Date: Tue, 21 Feb 2023 01:51:13 -0700
Subject: [PATCH] define -> frozen

---
 src/allmydata/grid_manager.py           | 3 ++-
 src/allmydata/test/test_grid_manager.py | 7 +++++--
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/allmydata/grid_manager.py b/src/allmydata/grid_manager.py
index fb70a6d02..7f1c6eda5 100644
--- a/src/allmydata/grid_manager.py
+++ b/src/allmydata/grid_manager.py
@@ -25,11 +25,12 @@ from allmydata.util import (
 
 from attrs import (
     define,
+    frozen,
     Factory,
 )
 
 
-@define
+@frozen
 class SignedCertificate(object):
     """
     A signed certificate.
diff --git a/src/allmydata/test/test_grid_manager.py b/src/allmydata/test/test_grid_manager.py
index 0f8df69d6..c282d1237 100644
--- a/src/allmydata/test/test_grid_manager.py
+++ b/src/allmydata/test/test_grid_manager.py
@@ -434,11 +434,14 @@ class GridManagerInvalidVerifier(SyncTestCase):
         An incorrect signature is rejected
         """
         # make signature invalid
-        self.cert0.signature = invalid_signature.encode("ascii")
+        invalid_cert = SignedCertificate(
+            self.cert0.certificate,
+            invalid_signature.encode("ascii"),
+        )
 
         verify = create_grid_manager_verifier(
             [self.gm._public_key],
-            [self.cert0],
+            [invalid_cert],
             ed25519.string_from_verifying_key(self.pub0),
             bad_cert = lambda key, cert: None,
         )