It's best to set up a new virtual environment for nexxT builds and development:

    python3 -m venv venv

It is assumed that this environment is activated for the following commands.
    
Build dependencies:
- QT5: set QTDIR for identifying the QT version
- shiboken2_generator: this is referenced in requirements.txt, but you have to 
  build or download this manually. The easiest option is to download it from 
  downloaded from 
  https://download.qt.io/official_releases/QtForPython/shiboken2-generator/
  This is working for windows and debian builds and probably also for more,
  even though the PySide2 project doesn't recommend to use the binary 
  distribution

You can use pip to install the required dependencies like that
  
    pip install -r requirements.txt --find-links /path/of/shiboken2_generator

Afterwards you should be able to use "scons -j 8 .." to build and install nexxT
binaries and c extensions.

Note that the project uses pylint for coding style checks. Use 
    
    pylint_nexxT[.bat|.sh] 
    
for generating a report.

For running tests, use

    pytest_nexxT[.bat|.sh]
    
scripts.