> loading initial cache file ../settings.cmake
> CMake Error: Error: generator : Ninja
> Does not match the generator used previously: Unix Makefiles
> Either remove the CMakeCache.txt file and CMakeFiles directory or choose a different binary directory.
 
These errors indicate that CMake already believes a project has been created in the target directory and that this project was a Makefile based project.  Is there any CMakeCache.txt files located anywhere in the project structure that may be causing CMake to get confused? Otherwise you could reinitialise the tutorial project and try initialising hello-world again and that would also fix your problem.