/usr/include/ is in libkf5calendarcore-dev 4:17.12.3-0ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/KF5/
/usr/include/KF5/KCalCore/
/usr/include/KF5/KCalCore/KCalCore/
/usr/include/KF5/KCalCore/KCalCore/Alarm
/usr/include/KF5/KCalCore/KCalCore/Attachment
/usr/include/KF5/KCalCore/KCalCore/Attendee
/usr/include/KF5/KCalCore/KCalCore/CalFilter
/usr/include/KF5/KCalCore/KCalCore/CalFormat
/usr/include/KF5/KCalCore/KCalCore/CalStorage
/usr/include/KF5/KCalCore/KCalCore/Calendar
/usr/include/KF5/KCalCore/KCalCore/CustomProperties
/usr/include/KF5/KCalCore/KCalCore/Duration
/usr/include/KF5/KCalCore/KCalCore/Event
/usr/include/KF5/KCalCore/KCalCore/Exceptions
/usr/include/KF5/KCalCore/KCalCore/FileStorage
/usr/include/KF5/KCalCore/KCalCore/FreeBusy
/usr/include/KF5/KCalCore/KCalCore/FreeBusyCache
/usr/include/KF5/KCalCore/KCalCore/FreeBusyPeriod
/usr/include/KF5/KCalCore/KCalCore/ICalFormat
/usr/include/KF5/KCalCore/KCalCore/Incidence
/usr/include/KF5/KCalCore/KCalCore/IncidenceBase
/usr/include/KF5/KCalCore/KCalCore/Journal
/usr/include/KF5/KCalCore/KCalCore/MemoryCalendar
/usr/include/KF5/KCalCore/KCalCore/OccurrenceIterator
/usr/include/KF5/KCalCore/KCalCore/Period
/usr/include/KF5/KCalCore/KCalCore/Person
/usr/include/KF5/KCalCore/KCalCore/Recurrence
/usr/include/KF5/KCalCore/KCalCore/RecurrenceRule
/usr/include/KF5/KCalCore/KCalCore/ScheduleMessage
/usr/include/KF5/KCalCore/KCalCore/SortableList
/usr/include/KF5/KCalCore/KCalCore/Sorting
/usr/include/KF5/KCalCore/KCalCore/Todo
/usr/include/KF5/KCalCore/KCalCore/VCalFormat
/usr/include/KF5/KCalCore/KCalCore/Visitor
/usr/include/KF5/KCalCore/kcalcore/
/usr/include/KF5/KCalCore/kcalcore/alarm.h
/usr/include/KF5/KCalCore/kcalcore/attachment.h
/usr/include/KF5/KCalCore/kcalcore/attendee.h
/usr/include/KF5/KCalCore/kcalcore/calendar.h
/usr/include/KF5/KCalCore/kcalcore/calfilter.h
/usr/include/KF5/KCalCore/kcalcore/calformat.h
/usr/include/KF5/KCalCore/kcalcore/calstorage.h
/usr/include/KF5/KCalCore/kcalcore/customproperties.h
/usr/include/KF5/KCalCore/kcalcore/duration.h
/usr/include/KF5/KCalCore/kcalcore/event.h
/usr/include/KF5/KCalCore/kcalcore/exceptions.h
/usr/include/KF5/KCalCore/kcalcore/filestorage.h
/usr/include/KF5/KCalCore/kcalcore/freebusy.h
/usr/include/KF5/KCalCore/kcalcore/freebusycache.h
/usr/include/KF5/KCalCore/kcalcore/freebusyperiod.h
/usr/include/KF5/KCalCore/kcalcore/icalformat.h
/usr/include/KF5/KCalCore/kcalcore/incidence.h
/usr/include/KF5/KCalCore/kcalcore/incidencebase.h
/usr/include/KF5/KCalCore/kcalcore/journal.h
/usr/include/KF5/KCalCore/kcalcore/kcalcore_export.h
/usr/include/KF5/KCalCore/kcalcore/memorycalendar.h
/usr/include/KF5/KCalCore/kcalcore/occurrenceiterator.h
/usr/include/KF5/KCalCore/kcalcore/period.h
/usr/include/KF5/KCalCore/kcalcore/person.h
/usr/include/KF5/KCalCore/kcalcore/recurrence.h
/usr/include/KF5/KCalCore/kcalcore/recurrencerule.h
/usr/include/KF5/KCalCore/kcalcore/schedulemessage.h
/usr/include/KF5/KCalCore/kcalcore/sortablelist.h
/usr/include/KF5/KCalCore/kcalcore/sorting.h
/usr/include/KF5/KCalCore/kcalcore/supertrait.h
/usr/include/KF5/KCalCore/kcalcore/todo.h
/usr/include/KF5/KCalCore/kcalcore/vcalformat.h
/usr/include/KF5/KCalCore/kcalcore/visitor.h
/usr/include/KF5/kcalcore_version.h