Try to understand why most buildbots suddenly turned to red.
Undo the only change that might have unexpected effects.
To be followed.
diff --git a/Lib/threading.py b/Lib/threading.py
index eebe10a..b7b7023 100644
--- a/Lib/threading.py
+++ b/Lib/threading.py
@@ -535,7 +535,8 @@
# test_threading.test_no_refcycle_through_target when
# the exception keeps the target alive past when we
# assert that it's dead.
- self.__exc_clear()
+ # XXX Temporary experiment
+ # self.__exc_clear()
finally:
with _active_limbo_lock:
self.__stop()