Partition is mounted read-only on UT,
you cannot write everywhere, there are default writeable directories though available with your app namespace by using
QStandardPath api
QStandardPaths::AppDataLocation -> ~./local/share/yourappnamespace
QStandardPaths::CacheLocation -> ~.cache/yourappnamespace
see http://docs.ubports.com/en/latest/appdev/guides/writeable-dirs.html