Ubuntu – Why does forcing Qt applications to use GTK theme makes those apps startup slowly


I noticed whenever I force qt applications to use any GTK theme on Ubuntu 19.10 by adding the line export QT_QPA_PLATFORMTHEME=gtk2 to .profile, the startup time goes from 1-3 seconds to 20+ seconds for vlc and qbittorrent. Why is this and is there anything I can do?

I have ran
sudo apt install qt5ct
sudo apt install qt5-style-plugins

Best Answer

  • On Ubuntu based Pop OS this same issue is occuring, but only on fresh 19.10 installs and not on 19.04 or 19.10 upgrades from 19.04. So if you had upgraded your system to 19.10 if the issue is not Pop OS specific then you likely won't experience the issue like those on fresh installs.