Hi Rudolf!
Package: libqt5serialport5
Version: 5.7.1 is available, 5.9.x is missing
I run Debian stable and need libqt5serialport5 version 5.9 instead of
5.7 - other parts of Debian stable do not accept qt5 version lower than 5.9
Actually stable only has 5.7. Due to the nature of Qt we can't provide backports. And sadly we do not have PPA-like infrastructure like Ubuntu does, so we can't provide unofficial backports.
I'm so closing this bug.