Block the sys.exc_clear -3 warning from threading.py.
diff --git a/Lib/threading.py b/Lib/threading.py
index eebe10a..516e22d 100644
--- a/Lib/threading.py
+++ b/Lib/threading.py
@@ -8,6 +8,7 @@
del _sys.modules[__name__]
raise
+import warnings
from time import time as _time, sleep as _sleep
from traceback import format_exc as _format_exc
from collections import deque
@@ -24,6 +25,12 @@
del thread
+# sys.exc_clear is used to work around the fact that except blocks
+# don't fully clear the exception until 3.0.
+warnings.filterwarnings('ignore', category=DeprecationWarning,
+ module='threading', message='sys.exc_clear')
+
+
# Debug support (adapted from ihooks.py).
# All the major classes here derive from _Verbose. We force that to
# be a new-style class so that all the major classes here are new-style.