hdp@hdp-virtual-machine:~/fcitx-qt5$ make [ 0%] Built target fcitx-scan-addons.target [ 0%] Built target fcitx-modules.target [ 3%] Automatic MOC for target FcitxQt5DBusAddons [ 3%] Built target FcitxQt5DBusAddons_autogen [ 6%] Linking CXX shared library libFcitxQt5DBusAddons.so CMakeFiles/FcitxQt5DBusAddons.dir/fcitxqtconnection.cpp.o: In function `FcitxQtConnectionPrivate::FcitxQtConnectionPrivate(FcitxQtConnection*)': fcitxqtconnection.cpp:(.text+0x2bb): undefined reference to `vtable for FcitxQtConnectionPrivate' CMakeFiles/FcitxQt5DBusAddons.dir/fcitxqtconnection.cpp.o: In function `FcitxQtConnectionPrivate::~FcitxQtConnectionPrivate()': fcitxqtconnection.cpp:(.text+0x4e4): undefined reference to `vtable for FcitxQtConnectionPrivate' collect2: error: ld returned 1 exit status make[2]: *** [dbusaddons/libFcitxQt5DBusAddons.so.1.0] Error 1 make[1]: *** [dbusaddons/CMakeFiles/FcitxQt5DBusAddons.dir/all] Error 2 make: *** [all] Error 2 hdp@hdp-virtual-machine:~/fcitx-qt5$