Issue #1759169: Drop _XOPEN_SOURCE on Solaris.
diff --git a/Misc/NEWS b/Misc/NEWS
index 0de7e3b..17f7164 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -87,6 +87,10 @@
   leading to a failure where four directories were expected for site-packages
   instead of two in a non-framework build.
 
+Build
+-----
+
+- Issue #1759169: Drop _XOPEN_SOURCE on Solaris.
 
 What's New in Python 2.7 beta 2?
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