/usr/include/kdevplatform/project/ is in kdevplatform-dev 5.0.3-1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/kdevplatform/project/abstractfilemanagerplugin.h
/usr/include/kdevplatform/project/builderjob.h
/usr/include/kdevplatform/project/helper.h
/usr/include/kdevplatform/project/importprojectjob.h
/usr/include/kdevplatform/project/interfaces/
/usr/include/kdevplatform/project/interfaces/ibuildsystemmanager.h
/usr/include/kdevplatform/project/interfaces/iprojectbuilder.h
/usr/include/kdevplatform/project/interfaces/iprojectfilemanager.h
/usr/include/kdevplatform/project/interfaces/iprojectfilter.h
/usr/include/kdevplatform/project/interfaces/iprojectfilterprovider.h
/usr/include/kdevplatform/project/projectbuildsetmodel.h
/usr/include/kdevplatform/project/projectchangesmodel.h
/usr/include/kdevplatform/project/projectconfigpage.h
/usr/include/kdevplatform/project/projectconfigskeleton.h
/usr/include/kdevplatform/project/projectexport.h
/usr/include/kdevplatform/project/projectfiltermanager.h
/usr/include/kdevplatform/project/projectitemlineedit.h
/usr/include/kdevplatform/project/projectmodel.h
/usr/include/kdevplatform/project/projectutils.h