https://bugs.gentoo.org/947606
TODO: needs upstreaming
--- a/src/plugins/multimedia/gstreamer/common/qgstreameraudiooutput.cpp
+++ b/src/plugins/multimedia/gstreamer/common/qgstreameraudiooutput.cpp
@@ -13,2 +13,3 @@
 #if QT_CONFIG(pulseaudio)
+#  include <QVersionNumber>
 #  include <pulse/version.h>