#6990: clear threading.local's key only after its thread state is removed:
fixes local subclasses leaving old state around after a ref cycle GC which
could be recycled by new locals
diff --git a/Misc/NEWS b/Misc/NEWS
index 70623b2..98beb4e 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,9 @@
Core and Builtins
-----------------
+- Issue #6990: Fix threading.local subclasses leaving old state around
+ after a reference cycle GC which could be recycled by new locals.
+
- Issue #6300: unicode.encode, unicode.decode, str.decode, and str.encode now
take keyword arguments.