Hey, ah now i see the problem: > extra/kipi-plugins/CMakeLists.txt:116 (find_package)
find_package(KF5 ${KF5_MIN_VERSION} OPTIONAL_COMPONENTS Archive # for FlashExport ThreadWeaver # for Panorama CalendarCore # for Calendar ) ^^ here it tries to load CalendarCore with >"5.1.0" jepp this is a bug on kipi-plugins side. It must changed to: find_package(KF5CalendarCore 4.81.0 OPTIONAL) or find_package(KF5 4.81.0 OPTIONAL_COMPONENTS CalendarCore ) my first guess was, that the find_package silently fails and the next line checks the kcalccore version in more depth. regards, sandro PS: btw. I'm release manager of kdepim so also of kcalcore and i can tell you for sure, that there is no 5 version for kcalcore released now