Hi Elliot, in the gitlab text I found a letter error:
here: sudo zypper in libQt5Widgets-devel libqt5-qtbase-common-devel libqt5-qtserialport-devel libQt5SerialPort5 qcustomplot-devel libqcustomplot2 libQt5PrintSupport-devel libqt5-qtmultimedia-devel lv2-devel libopus-devel eigen3-devel libQt5Xml-devel portaudio-devel rtaudio-devel libqt5-qtgamepad-devel
libQt5Gamepad5
it must be: develel
Wilhelm, DF7GT