/usr/include/ is in libkf5calendarutils-dev 4:17.12.3-0ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/KF5/KCalUtils/
/usr/include/KF5/KCalUtils/KCalUtils/
/usr/include/KF5/
/usr/include/KF5/KCalUtils/KCalUtils/DndFactory
/usr/include/KF5/KCalUtils/KCalUtils/HtmlExport
/usr/include/KF5/KCalUtils/KCalUtils/ICalDrag
/usr/include/KF5/KCalUtils/KCalUtils/IncidenceFormatter
/usr/include/KF5/KCalUtils/KCalUtils/RecurrenceActions
/usr/include/KF5/KCalUtils/KCalUtils/Scheduler
/usr/include/KF5/KCalUtils/KCalUtils/Stringify
/usr/include/KF5/KCalUtils/KCalUtils/VCalDrag
/usr/include/KF5/KCalUtils/kcalutils/
/usr/include/KF5/KCalUtils/kcalutils/HTMLExportSettings
/usr/include/KF5/KCalUtils/kcalutils/dndfactory.h
/usr/include/KF5/KCalUtils/kcalutils/htmlexport.h
/usr/include/KF5/KCalUtils/kcalutils/htmlexportsettings.h
/usr/include/KF5/KCalUtils/kcalutils/icaldrag.h
/usr/include/KF5/KCalUtils/kcalutils/incidenceformatter.h
/usr/include/KF5/KCalUtils/kcalutils/kcalutils_export.h
/usr/include/KF5/KCalUtils/kcalutils/recurrenceactions.h
/usr/include/KF5/KCalUtils/kcalutils/scheduler.h
/usr/include/KF5/KCalUtils/kcalutils/stringify.h
/usr/include/KF5/KCalUtils/kcalutils/vcaldrag.h
/usr/include/KF5/kcalutils_version.h