cmake: 
-- The C compiler identification is GNU 7.3.0
-- The CXX compiler identification is GNU 7.3.0
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Found OpenGL: /usr/lib/x86_64-linux-gnu/libOpenGL.so   
-- Found GLUT: /usr/lib/x86_64-linux-gnu/libglut.so  
-- Configuring done
-- Generating done
-- Build files have been written to: /out

make: 
Scanning dependencies of target p3_part1
[ 25%] Building CXX object CMakeFiles/p3_part1.dir/main.cpp.o
[ 50%] Linking CXX executable p3_part1
[ 50%] Built target p3_part1
Scanning dependencies of target p3_part2
[ 75%] Building CXX object CMakeFiles/p3_part2.dir/WinMain.cpp.o
In file included from /in/WinMain.cpp:3:0:
/in/util.h:2:10: fatal error: windows.h: No such file or directory
 #include <windows.h>
          ^~~~~~~~~~~
compilation terminated.
CMakeFiles/p3_part2.dir/build.make:62: recipe for target 'CMakeFiles/p3_part2.dir/WinMain.cpp.o' failed
make[2]: *** [CMakeFiles/p3_part2.dir/WinMain.cpp.o] Error 1
CMakeFiles/Makefile2:104: recipe for target 'CMakeFiles/p3_part2.dir/all' failed
make[1]: *** [CMakeFiles/p3_part2.dir/all] Error 2
Makefile:83: recipe for target 'all' failed
make: *** [all] Error 2