Install Qt

You can use the precompiled version of Qt (see Precompiled Qt) or you can compile Qt by yourself (see Qt from sources).

Precompiled Qt

Download Qt from https://www.qt.io

Example with the free version of Qt:

chmod 700 qt-unified-linux-x64-3.1.1-online.run
./qt-unified-linux-x64-3.1.1-online.run

Install Qt to /opt/Qt.

Choose the components that you need: Ex. Qt 5.12.6 / Desktop gcc 64-bit.

Qt libraries:

Add to '/etc/ld.so.conf' the Qt library directory. Example:

/opt/Qt/5.12.6/gcc_64/lib

Run 'ldconfig' to reload the cache.

Setup path:

Edit to your '~/.bash_profile' and append to the PATH variable the Qt bin path. Example:

PATH=$HOME/bin:$PATH:/usr/java/bin:/opt/Qt/5.12.6/gcc_64/bin

Qt environment variable:

Add the line

export QT_XKB_CONFIG_ROOT=/opt/share/X11/xkb

to one of the following files

~/.bash_profile
~/.myxinitrc
~/xfce4 or ~/fluxbox (depending on what you use)

Restart the desktop or logout/login to activate the environment variable.

Qt from sources

Download, compile and install to '/opt/Qt':

git clone git://code.qt.io/qt/qt5.git

cd qt5
./init-repository

./configure -opensource -release -qt-pcre --prefix=/opt/Qt --assimp=no --nomake=examples -skip qtwebengine

make -j 4 && make install