some months later...
I think I solved this problem, I changed the line
include_directories( ${${LIBNAME}_INCLUDE_DIR} )
by
include_directories( ${${LIBNAME}_INCLUDEDIR} )
after noticing how includedir
is typed in CEGUI-0.pc
...
includedir=${prefix}/include/cegui-0
I don't get the "no file found error" for #include <CEGUI/CEGUI.h>
anymore. I will try to do a hell-o world with CEGUI in my program next days. If you have any comment plz do.