QT5 lead to too big fonts

[efa]

switching from QT4 to QT5:
$ qtchooser -print-env
$ export QT_SELECT=qt4 # switch to QT4
$ export QT_SELECT=qt5 # switch to QT5

lead to font that goes out of windows and dialog box, see attach.

This is LMDE4 (Debian 10 Buster)
QT5:

QT4:

[efa]

ma da te si vedono le scritte intere con le QT5 ?

[efa]

Welcome back Alberto!

I just build on Debian 12, where libqt4 is missing. The available package are:
qtbase5-dev
qtbase5-private-dev
qt-base6-dev
So please fix the note about install
libqt5-private-dev on https://github.com/alus-it/AirspaceConverter main page

Here defining:
QT_SELECT=qt4
lead to a compile error.
Defining to qt5 or left undefined, build using QT5.

Now the trouble is even worse than before, as the label of buttons are all cut, see attach