Compile error with latest master

Hi all,

I tried to compile latest KWin master yesterday, but I'm hitting a compile 
error I do not understand. CMake does not complain about anything missing.

[714/2304] Building CXX object src/wayland/CMakeFiles/
WaylandProtocols_xml.dir/qwayland-server-wayland.cpp.o
FAILED: src/wayland/CMakeFiles/WaylandProtocols_xml.dir/qwayland-server-
wayland.cpp.o <snip>
In file included from /home/martin/build/kwin/src/wayland/qwayland-server-
wayland.cpp:4:
/home/martin/build/kwin/src/wayland/qwayland-server-wayland.h:8:10: fatal 
error: wayland-wayland-server-protocol.h: No such file or directory
    8 | #include "wayland-wayland-server-protocol.h"
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.

I get several of those includes not found.

Any hints on what is missing?

Cheers
Martin