qDebug() information does not show in Application Output

qDebug() information stops showing up in Qt Creator, after I did something I did not know to impact Qt Creator…
Tutorial
Author

Yujie Wang

Published

April 30, 2025

Yesterday, I removed some packages from Linux, or something else happened… The outcome was that I could not see any qDebug() messages any longer in the tab “Application Output” of Qt Creator. I did not know to date what triggered the issue. It might be because of my switching to KDE Plasma from Cinnamon, but I do not bother to install Cinnamon back…

After searching for potential solutions for quite a while, I came across this: https://bbs.archlinux.org/viewtopic.php?id=259035. According to d_fajardo, we can change the setting of Qt Creator. Since I am using Qt 6, I adapted the changes to

Qt Creator > Edit > Preferences... > Kits

Then in the Kits tab, you will find a few kits, such as Python 3.13.2 in auto detected and Desktop (default) in Manual…

If you click Desktop (default), for example, you will find

Environment: Edit Build Environment... Edit Run Environment...

Then change the build and run environments, and add the line

QT_ASSUME_STDERR_HAS_CONSOLE=1

Now, you will have the qDebug() information back!