Replying to myself: The bugrepport said is is fixed for 5.10.1 https://bugreports.qt.io/browse/QTBUG-64121 And it can be made to work with correct folder permissions : $ ls -ld /etc/config/ drwxr-xr-x 2 root root 4096 avril 1 11:15 /etc/config/ $ sudo chgrp pi /etc/config/ $ sudo chmod g+w /etc/config/ $ ls -ld /etc/cleandrop/ drwxrwxr-x 2 root pi 4096 avril 1 11:15 /etc/config/ resolving simlink doesn't helps // resolve symlink // https://bugreports.qt.io/browse/QTBUG-64121 QFileInfo info(_configuration_file); if (info.isSymLink()) _configuration_file = info.symLinkTarget(); So I removed this fix, and fixed the folder permission and it worked.