Issue #11915: threading.RLock()._release_save() raises a RuntimeError if the
lock was not acquired.
diff --git a/Misc/NEWS b/Misc/NEWS
index 8aac765..62aaea4 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -113,6 +113,9 @@
 Library
 -------
 
+- Issue #11915: threading.RLock()._release_save() raises a RuntimeError if the
+  lock was not acquired.
+
 - Issue #11258: Speed up ctypes.util.find_library() under Linux by a factor
   of 5 to 10.  Initial patch by Jonas H.