The input modules for Qt4 and Qt5 seem to be installed: [mfabian@localhost lineedits]$ rpm -qf /usr/lib64/qt4/plugins/inputmethods/libqtim-ibus.so ibus-qt-1.3.3-24.fc32.x86_64 [mfabian@localhost lineedits]$ rpm -qf /usr/lib64/qt5/plugins/platforminputcontexts/libibusplatforminputcontextplugin.so qt5-qtbase-gui-5.14.2-5.fc32.x86_64 [mfabian@localhost lineedits]$ I did set the environment variable QT_IM_MODULE=ibus I used the lineedits examples for testing: [mfabian@localhost lineedits]$ rpm -qf /usr/lib64/qt4/examples/widgets/lineedits/lineedits qt-examples-4.8.7-52.fc32.x86_64 [mfabian@localhost lineedits]$ rpm -qf /usr/lib64/qt5/examples/widgets/widgets/lineedits/lineedits qt5-qtbase-examples-5.14.2-5.fc32.x86_64 [mfabian@localhost lineedits]$ I am using ibus-anthy for testing ibus input, but it doesn’t matter which ibus engine is used. When using the Gnome Xorg desktop, I can input with ibus-anthy into both the Qt5 and the Qt4 lineedit examples. With the Qt4 lineedit example, I can choose by opening the context menu with the right mouse button between using xim and ibus. Both works. Qt5 does not support xim, so this option does not exist, but ibus input works. Now when using the Gnome Wayland desktop, I can only input when using the "xim" option in Qt4. With the "ibus" option in Qt4, ibus input does not work. And in Qt5, ibus input does not work. To summarize: ============= ibus input using the ibus modules does not work in Qt4 and Qt5 when Gnome Wayland is used, it works in Gnome Xorg.
Copying this file makes it work (Fujiwara San told me that): [mfabian@localhost bus]$ cp 8e6ab773e4094f2db140fb3b3068ba27-unix-wayland-0 8e6ab773e4094f2db140fb3b3068ba27-unix-0 [mfabian@localhost bus]$ 8e6ab773e4094f2db140fb3b3068ba27-unix-0 did already exist, probably from the previous log in into the Gnome Wayland session. But it contained wrong information.
I will fix ibus-qt after qt5 is fixed. *** This bug has been marked as a duplicate of bug 1832086 ***