One of the 100+(?) update sessions during the past ~ 10 weeks rendered Qt-based programs useless, not working.
This seems to have happened to others in the past 3 years. None of the reported solutions, if any, seems suited for my system, but point into the direction that the configuration might have been corrupted by one (or more) of the updates.
Current system: Linux 6.5.5-1-MANJARO, X11, Gnome 44.5
And qt-theming.sh that I found in /etc/profile.d:
# Available options: gtk2, gnome, kde, qt5ct, xcb
# Note: Don't use in combination with QT_STYLE_OVERRIDE
# Available styles: HighContrastInverse, HighContrast, Adwaita-HighContrastInverse,
# Adwaita-HighContrast, Adwaita-Dark, Adwaita, kvantum-dark, kvantum, qt5ct-style,
# Windows, Fusion
# Note: Don't use in combination with QT_QPA_PLATFORMTHEME
Perhaps there are other components of the configuration that I haven’t found.
Well, in those tutorials, for example, you might have noticed that placing all that pasted text between backticks (```), top and bottom, would have produced a more human-readable preformatted text container:
Hi, I am an example of preformatted text.
Each line of the original text stays on it own
line, and makes it easier to read.
The information was important as it helps others to help you. For example, knowing your system information may help someone decide if an issue is a commonly known problem, or specific to your system.
We’re here to help, if we can, but you need to help us too; we’re not mind-readers.
All the Qt applications don’t work anymore.
Or, they pretend to work (open and close (on clicking the “×” in Gnome’s extra decoration (title bar)) without complaint), but the graphics is corrupt and clicks in the application’s window hardly work at all, at least don’t work as they did before.
E.g. settings manager:
Icon and title clipped and clicking has either no effect or effects nothing but an eternal hourglass mouse pointer.
And they don’t send error messages - journalctl doesn’t get any related information.
(If any reader knows an easy markdown editor with preview and integrated cheat sheet, please let me know!)
The problem seems to be in the system configuration (hopefully not deeper) and affects all users.
If I knew where to find all files for Qt-related settings …
(the (only) one I’ve found so far and have reported in #1, doesn’t seem to affect it - or I don’t know how to change that file effectively)
… I could check them one by one and try to fix the problem there.
The original of that config-file, /etc/profile.d/qt-theming.sh is dated 23-08-30.
So I assume that the update of 8/30 has caused the problems.
(there have been more than 50 further updates in the meantime)
The point is, that’s a script; and it seems as it should be, at first glance. It’s likely that didn’t need to be upgraded, so it wasn’t. If your theory is based solely on the content of that script, it’s probably wrong.
The problem is something else. Being that you’re using Gnome, which I have no interest in, it’s likely I’m no direct help, but I’m sure someone else might be. Help them as much as you can. If someone asks you do do something, do it, and more importantly, report back the results.
Well, didn’t take that long.
… and didn’t seem to keep the promise: most of the files show hardly any relation to Qt-fine-tuning.
And most are specific for one (and only that one) application: so cannot contain a setting affecting all Qt-applications simultaneously.
BUT: there’s one exception.
Have seen that earlier, but never thought it could have an effect for my ordinary 2K-Monitor (all but high-dpi).
But It has!!
Setting the QT_AUTO_SCREEN_SCALE_FACTOR (from 1.0) to 0.8 reveals a larger part of the Qt-application’s window …
I’m afraid it’s not that simple. But it points in the decisive direction.
It’s about a global scale factor. And the one I used to get Gnome using the screen estate in a sensible way, i. e. not destroying it (the screen estate) by abusing 60% of it for its huge decorations.
… and yes I see why Gnome has lost popularity. Versions >4 make it more and more useless. But it’s the only DE I found that allows to have two docks, a horizontal and a vertical one at 2 sides of the screen (via its extensions dash to panel and dash to dock) and an applications overview without a multiply nested menu.
Need to find another way to scale the Gnome - back to a gnome from the bloated giant.
p.s.: This topic is definitely solved - at a high price.
Fear that current Gnomes require an 8k Monitor or better to become sensible - but that would be a new topic.
(Still don’t know why it had worked before that update.)
Don’t get it to work: “xrandr: Configure crtc 0 failed”
Would probably need umpteen additional settings.
And: " This article or section is out of date … Gnome Shell Toolkit … looks unmaintained since 2009"
But I don’t think that this direction to fix these new display problems of Qt applications will work ever.
My Notebook with a <2 k display works perfectly including Qt with Linux 6.4.14-1 and Gnome 44.4 … and doesn’t complain about pending updates although I just switched it on after almost 3 months of inactivity.
→ All the ~100 update sessions since end of August on this (“desktop”) computer ¹ seem to have tried Linux 6.5 related bug fixing - to no avail.
¹) currently with Linux 6.5.5-1 and Gnome 44.5
p.s.: Well, the notebook does offer almost 3GB of updates …
But I’m not going to kill my only flawlessly working Manjaro installation before I’ve prepared the space for Timeshift and configured it.