/usr/lib/ is in libkf5kontactinterface-dev 17.12.3-0ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/x86_64-linux-gnu/
/usr/lib/x86_64-linux-gnu/cmake/
/usr/lib/x86_64-linux-gnu/cmake/KF5KontactInterface/
/usr/lib/x86_64-linux-gnu/cmake/KF5KontactInterface/KF5KontactInterfaceConfig.cmake
/usr/lib/x86_64-linux-gnu/cmake/KF5KontactInterface/KF5KontactInterfaceConfigVersion.cmake
/usr/lib/x86_64-linux-gnu/cmake/KF5KontactInterface/KF5KontactInterfaceTargets-debian.cmake
/usr/lib/x86_64-linux-gnu/cmake/KF5KontactInterface/KF5KontactInterfaceTargets.cmake
/usr/lib/x86_64-linux-gnu/qt5/
/usr/lib/x86_64-linux-gnu/qt5/mkspecs/
/usr/lib/x86_64-linux-gnu/qt5/mkspecs/modules/
/usr/lib/x86_64-linux-gnu/qt5/mkspecs/modules/qt_KontactInterface.pri
/usr/lib/x86_64-linux-gnu/libKF5KontactInterface.so