>>> /usr/etc/xdg/marble.knsrc This happens in 16.12.x as well as git master from today.
The problem itself is triggered because KDEInstallDirs.cmake from extra-cmake-modules[1] sets KDE_INSTALL_SYSCONFDIR to ${CMAKE_INSTALL_SYSCONFDIR} which is set by GNUInstallDirs.cmake[2] as "etc" and interpreted as a relative path to CMAKE_INSTALL_PREFIX. [1] https://github.com/KDE/extra-cmake-modules/blob/master/kde-modules/KDEInstallDirs.cmake [2] https://github.com/KDE/marble/blob/master/CMakeLists.txt#L14