src/lua/lunar.h:12:10: fatal error: lua.h: No such file or directory

[a17r]

We are in the process of killing Qt4, unfortunately 1.6.0 fails to build even on Gentoo currently...

sr/lib64/qt5/mkspecs/linux-g++ -o .obj/frame.o src/lua/frame.cpp
In file included from src/lua/frame.h:23:0,
                 from src/lua/frame.cpp:18:
src/lua/lunar.h:12:10: fatal error: lua.h: No such file or directory
 #include "lua.h"
          ^~~~~~~
compilation terminated.
make: *** [Makefile:2720: .obj/frame.o] Error 1

lua-5.2 headers are slotted:

/usr/include/lua5.2
/usr/include/lua5.2/lauxlib.h
/usr/include/lua5.2/lua.h
/usr/include/lua5.2/lua.hpp
/usr/include/lua5.2/luaconf.h
/usr/include/lua5.2/lualib.h

Is your ebuild/qmake config pre-dating slotted lua?

See also: https://bugs.gentoo.org/644424

[Osfognarg]

Don't know if this helps, but I got past this particular error by changing the includes in lunar.h from

#include "lua.h"
#include "lualib.h"
#include "lauxlib.h"

to

#include "/usr/include/lua5.2/lua.h"
#include "/usr/include/lua5.2/lualib.h"
#include "/usr/include/lua5.2/lauxlib.h"

It's a minute's work and the error stopped appearing after that.