Para openSUSE Leap 15.2 execute o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/home:rhabacker:branches:windows:mingw:win32:Qt511/openSUSE_Leap_15.2/home:rhabacker:branches:windows:mingw:win32:Qt511.repo
zypper refresh
zypper install mingw32-libqt5-qtbase
Para openSUSE Leap 15.1 execute o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/home:rhabacker:branches:windows:mingw:win32:Qt511/openSUSE_Leap_15.1/home:rhabacker:branches:windows:mingw:win32:Qt511.repo
zypper refresh
zypper install mingw32-libqt5-qtbase