/usr/lib/ is in libkf5calendarcore-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/KF5CalendarCore/
/usr/lib/x86_64-linux-gnu/cmake/KF5CalendarCore/KF5CalendarCoreConfig.cmake
/usr/lib/x86_64-linux-gnu/cmake/KF5CalendarCore/FindLibIcal.cmake
/usr/lib/x86_64-linux-gnu/cmake/KF5CalendarCore/KF5CalendarCoreTargets-debian.cmake
/usr/lib/x86_64-linux-gnu/cmake/KF5CalendarCore/KF5CalendarCoreTargets.cmake
/usr/lib/x86_64-linux-gnu/cmake/KF5CalendarCore/KF5CalendarCoreConfigVersion.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_KCalCore.pri
/usr/lib/x86_64-linux-gnu/libKF5CalendarCore.so