diff -urN testtools-2.4.0/testtools/_compat2x.py testtools-2.4.0-new/testtools/_compat2x.py
--- testtools-2.4.0/testtools/_compat2x.py	2015-11-08 01:27:33.000000000 +0800
+++ testtools-2.4.0-new/testtools/_compat2x.py	1970-01-01 08:00:00.000000000 +0800
@@ -1,17 +0,0 @@
-# Copyright (c) 2011 testtools developers. See LICENSE for details.
-
-"""Compatibility helpers that are valid syntax in Python 2.x.
-
-Only add things here if they *only* work in Python 2.x or are Python 2
-alternatives to things that *only* work in Python 3.x.
-"""
-
-__all__ = [
-    'reraise',
-    ]
-
-
-def reraise(exc_class, exc_obj, exc_tb, _marker=object()):
-    """Re-raise an exception received from sys.exc_info() or similar."""
-    raise exc_class, exc_obj, exc_tb
-
diff -urN testtools-2.4.0/testtools/compat.py testtools-2.4.0-new/testtools/compat.py
--- testtools-2.4.0/testtools/compat.py	2018-04-05 07:27:14.000000000 +0800
+++ testtools-2.4.0-new/testtools/compat.py	2021-08-06 10:55:13.294527126 +0800
@@ -33,10 +33,7 @@
 # To let setup.py work, make this a conditional import.
 linecache = try_import('linecache2')
 
-try:
-    from testtools import _compat2x as _compat
-except SyntaxError:
-    from testtools import _compat3x as _compat
+from testtools import _compat3x as _compat
 
 reraise = _compat.reraise