QWayland 5.9.0 from git sources cannot be compiled on linux.
There is an error during compilation of qtwayland/src/hardwareintegration/compositor/libhybris-egl-server/libhybriseglserverbufferintegration.cpp
Assuming QWaylandCompositor is defined here qtwayland/src/compositor/compositor_api/qwaylandcompositor.h
There is indeed no member waylandDisplay() but there is a member display() with type ::wl_display
It seems to have been changed 7 months ago in the following commit.
If you change the source to
It compile again.