diff --git a/share/qtcreator/gdbmacros/dumper.py b/share/qtcreator/gdbmacros/dumper.py
index 1e805ef825f370423752d4dddae1459fecefc67e..a59becb476fb4aabfd49c25a29d3a23c542d2898 100644
--- a/share/qtcreator/gdbmacros/dumper.py
+++ b/share/qtcreator/gdbmacros/dumper.py
@@ -863,11 +863,18 @@ class Item:
 #
 #######################################################################
 
-# This is a mapping from 'type name' to 'display alternatives'.
-
+# This is a cache mapping from 'type name' to 'display alternatives'.
 qqFormats = {}
+
+# This is a cache of all known dumpers.
 qqDumpers = {}
+
+# This is a cache of the namespace of the currently used Qt version.
+# FIXME: This is not available on 'bbsetup' time, only at 'bb' time.
 qqNs = ""
+
+# This is a cache of typenames->bool saying whether we are QObject
+# derived.
 qqQObjectCache = {}