Since we adopted versioned lib names (e.g. libqgis_core.so.1.1) it should be possible to have more than one version of QGIS coexsisting in the same CMAKE_INSTALL_PREFIX. This does indeed work and all ...
['/usr/share/qgis/python', '/home/mohamed/.local/share/QGIS/QGIS3/profiles/default/python', '/home/mohamed/.local/share/QGIS/QGIS3/profiles/default/python/plugins ...