I am using (and since more than 3 years now) a dual Xkb configuration using the following X11 configuration:
On my business laptop, I can then type on the integrated keyboard using azerty, and on an external keyboard using the bépo layout. This is really handy, and is working so far in every application I used, including Gtk application and Qt application (Qt<5), such as Qt Creator, that is compiled against Qt 4.8.5.
I am currently building a small application using Qt 5.3.2 and Qt Designer. A simple combo box doesn't want to use the bepo layout, it only uses the azerty one.
If I compile the same code using Qt 4.8.5, I can use both keyboards using their own layout, as expected.
It may be a duplicate of
I understand this is a corner case, but I see it as a regression from Qt 4.8.