/usr/include/KF5/ is in libkf5akonadiserver-dev 4:15.12.3-0ubuntu6.
This file is owned by root:root, with mode 0o755.
..
/usr/include/KF5/akonadi/
/usr/include/KF5/akonadi/abstractsearchplugin.h
/usr/include/KF5/akonadi/private/
/usr/include/KF5/akonadi/private/akonadiprivate_export.h
/usr/include/KF5/akonadi/private/capabilities_p.h
/usr/include/KF5/akonadi/private/dbus_p.h
/usr/include/KF5/akonadi/private/externalpartstorage_p.h
/usr/include/KF5/akonadi/private/imapparser_p.h
/usr/include/KF5/akonadi/private/imapset_p.h
/usr/include/KF5/akonadi/private/instance_p.h
/usr/include/KF5/akonadi/private/protocol_exception_p.h
/usr/include/KF5/akonadi/private/protocol_p.h
/usr/include/KF5/akonadi/private/scope_p.h
/usr/include/KF5/akonadi/private/standarddirs_p.h
/usr/include/KF5/akonadi/private/tristate_p.h
/usr/include/KF5/akonadi/private/xdgbasedirs_p.h