/usr/lib/ is in libkf5akonadi-dev 4:15.12.3-0ubuntu1.
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/KF5Akonadi/
/usr/lib/x86_64-linux-gnu/cmake/KF5Akonadi/KF5AkonadiTargets.cmake
/usr/lib/x86_64-linux-gnu/cmake/KF5Akonadi/KF5AkonadiTargets-debian.cmake
/usr/lib/x86_64-linux-gnu/cmake/KF5Akonadi/KF5AkonadiConfig.cmake
/usr/lib/x86_64-linux-gnu/cmake/KF5Akonadi/KF5AkonadiMacros.cmake
/usr/lib/x86_64-linux-gnu/cmake/KF5Akonadi/KF5AkonadiConfigVersion.cmake
/usr/lib/x86_64-linux-gnu/qt5/
/usr/lib/x86_64-linux-gnu/qt5/plugins/
/usr/lib/x86_64-linux-gnu/qt5/plugins/designer/
/usr/lib/x86_64-linux-gnu/qt5/plugins/designer/akonadi5widgets.so
/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_AkonadiAgentBase.pri
/usr/lib/x86_64-linux-gnu/qt5/mkspecs/modules/qt_AkonadiXml.pri
/usr/lib/x86_64-linux-gnu/qt5/mkspecs/modules/qt_AkonadiCore.pri
/usr/lib/x86_64-linux-gnu/qt5/mkspecs/modules/qt_AkonadiWidgets.pri
/usr/lib/x86_64-linux-gnu/libKF5AkonadiXml.so
/usr/lib/x86_64-linux-gnu/libKF5AkonadiCore.so
/usr/lib/x86_64-linux-gnu/libKF5AkonadiWidgets.so
/usr/lib/x86_64-linux-gnu/libKF5AkonadiAgentBase.so