stop the interaction of hypothesis and disttrial from hanging the tests

src/klein/test/test_plating.py

@@ -3,6 +3,7 @@
 """
 
 
+import atexit
 import json
 from string import printable
 from typing import Any
@@ -147,6 +148,17 @@ def jsonComposites(children):
 jsonObjects = st.recursive(jsonAtoms, jsonComposites, max_leaves=200)
 
 
+@atexit.register
+def invalidateJsonStrategy() -> None:
+    """
+    hypothesis RecursiveStrategy hangs on to a threadlocal object which causes
+    disttrial to hang for some reason.
+
+    Possibly related to U{this <https://github.com/python/cpython/pull/28525>}.
+    """
+    jsonObjects.limited_base._threadlocal = None
+
+
 def transformJSONObject(jsonObject, transformer):
     """
     Recursively apply a transforming function to a JSON serializable

tox.ini

@@ -56,6 +56,7 @@ basepython =
     py311: python3.11
     pypy3: pypy3
     pypy38: pypy3.8
+    pypy39: pypy3.9
 
 deps = {[default]deps}