Please pick a couple changes from https://invent.kde.org/libraries/mpvqt/-/compare/8802a82f...41883d09 to add to mpvqt.changes

Among these, there's cmake: require ecm version 6.0.0. That means the kf6_version defines needs to be updated and you can drop -DBUILD_WITH_QT6:BOOL=TRUE in the %build section

Thanks for your feedback. Updated spec and changes.