The Yocto recipe gives GPL as the license of MariaDB. The Qt Sql library implements its MySQL driver with MariaDB. Hence, it would be under GPL - and so would be all applications linking Qt Sql. Businesses would have to open-source their code. A disaster! So, what's wrong?
Episode 55: Better Built By Burkhard
Episode 51: Better Built By Burkhard
How hard can it be to write a Yocto recipe for building a Qt application with CMake? Actually, it turns out to be pretty hard. I have seen my fair share of slow-and-dirty workarounds (nothing is ever quick with Yocto,
Episode 48: Better Built By Burkhard. For user products, LGPL-3.0 grants users the right to install modified software on the device. For business products, it does not. This makes the choice between Qt LGPL and Qt Commercial for OEMs of machines, measurement instruments or medical devices obvious.
Most embedded Qt HMIs don't need the expensive commercial license but can be built with the free LGPL-3.0. Static linking is allowed with LGPL. B2B products need not allow the installation of modified Qt libs. Some Qt modules can be used under GPL albeit in separate processes.