specs: Tie Python 2 ->3 conversion loose ends.
diff --git a/specs/scripts/cxx2api.py b/specs/scripts/cxx2api.py
index 9720615..8056de4 100755
--- a/specs/scripts/cxx2api.py
+++ b/specs/scripts/cxx2api.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3