OS: Manjaro 20.1 Mikah
Kernel: x86_64 Linux 5.4.64-1-MANJARO
having some minor issues with QT applications when using a dark theme. So I wanted to change the QT_QPA_PLATFORMTHEME to gtk2 - just to check if it makes any difference. So I’ve changed it in /etc/environment, rebooted and checked again - still qt5ct.
My guess is that qt5ct itself sets the environment variable - afterwards. Due to my DE I can’t remove it without loosing some xfce settings from the manjoro team.
Is there a way to change the variable?
Thanks to some answers to my question it could be reduced to: What overwrites the environment variable QT_QPA_PLATFORMTHEME in manjaro
Sure. You can’t change it otherwise. From what I’ve read (arch forums & wiki) used to be a valid value.
But even it wasn’t: Setting an environment variable should work. (I’ve done that on my arch system without problems)
Question is: why should I install something else if:
I can’t find any information about it
Is not documented in the arch or manjaro wiki
It works on an original arch linux
concerning the environment.d folder in ~/.config: it doesn’t exist.
I guess I’d rather expect an explanation which code overwrites it. (because its not the first environment variable I’ve set - but the only one that seems not to be accepted. So I’m pretty sure it is getting overwritten.
The Desktop Environments ecosystem is not ideal and often very opinionated.
I understand your pain, for example GDM is unsetting my PATHs uppon login. Why the F@@ would it do that?? No idea but some smartasses from Gnome just decided it would be great to unset PATH when logging in.
In your case, some app or some mechanism does set/unset the QT platform variable.
Yep - I think so. Question is what or who. Your objection that qt5ct is not a service is right. Since I cant’t remove it, I think that some part of manjaro sets it - because it needs it for the Manjaro Notification Settings. (You can see it on the UI- that is a QT GUI)
FYI, I have no environment variables set on my netbook with Manjaro Xfce:
GTK theme: Adwaita-maia-dark
Kvantum theme: KvAdwaitaDark
Qt5 Settings Style: kvantum
This is now default in the Manjaro GNOME edition as Qt5ct isn’t seeing much development. It will also work well in Xfce. It will attempt to match Qt applications with the applied GTK theme. If you have Kvantum Manager (kvantum-qt5) installed, it will attempt to match a Kvantum theme.
Apparently you were looking in the wrong places. QGnomePlatform is developed by Fedora and I package it for Manjaro:
Maybe that’s the thing?
I recall at first we had to specify environment variables in order to use qt5ct or kvantum. If now such variables aren’t needed, would it mean those utilities are now automatically detected and used – and probably overwriting?
First thanks a lot for the elaborate explanation. And yes- I should’ve been more verbose about my problem:
I’m running xfce but developing and using QT5 applications. Some of the apps show white lines - something that I haven’t observed before. So I wanted to check out if qt5ct is maybe the culprit.