From the Arch Wiki I found that setting the environment variable DESKTOP_SESSION=gnome makes Qt4 apps use the system icon theme but not Qt5 apps. Also setting this in /etc/profile makes Xfce unbootable. Is there a way to make Qt4 and Qt5 apps use the same system icon theme? If not how do I install separate icon theme specially for Qt apps?
How to make Qt apps in Xubuntu 16.04 to use native icon theme?
ubuntu;qt;xubuntu;icons;qt4