Reply To cazfi
With the upcoming crosser-2.3 we will need multiple.
Actually, while testing this to confirm, it turns out that we are lucky and the Qt5 paths are found by pkg-config. So this is not (strictly) blocking move to crosser-2.3. It's still a good idea to implement this; I'm sure we will need it at some point, and would use it for proper use of crosser-2.3 too (not relying on just lucky path)
Our meson based build currently supports one include path and one library path in a cross file. With the upcoming crosser-2.3 we will need multiple. Add support for that.