Para openSUSE Tumbleweed execute o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/KDE:Qt:5.9/openSUSE_Tumbleweed/KDE:Qt:5.9.repo
zypper refresh
zypper install libqt5-qtserialbus
Para openSUSE Leap 42.3 execute o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/KDE:Qt:5.9/openSUSE_Leap_42.3/KDE:Qt:5.9.repo
zypper refresh
zypper install libqt5-qtserialbus
Para openSUSE Leap 15.0 execute o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/KDE:Qt:5.9/openSUSE_Leap_15.0/KDE:Qt:5.9.repo
zypper refresh
zypper install libqt5-qtserialbus