Impossible to draw because CGAL_USE_BASIC_VIEWER is not defined

n.m

I solved it by adding to ‍‍‍‍‍.pro file:

QMAKE_CXXFLAGS +=-DCGAL_USE_BASIC_VIEWER
LIBS+=-DCGAL_USE_BASIC_VIEWER

Another solution - put the line:

 #define CGAL_USE_BASIC_VIEWER

before all the CGAL includes in your cpp file.