Hi, Raef,
I added to the generator qualifier in CMakeLists.txt line 17. Since cmake is not my native language, I put in the full string, as you see. The string comes from the display of CMAKE_GENERATOR in the error message.
if(NOT ${CMAKE_GENERATOR} STREQUAL "Unix Makefiles" AND
NOT ${CMAKE_GENERATOR} STREQUAL "Visual Studio 16 2019" AND
NOT ${CMAKE_GENERATOR} STREQUAL "Ninja")
Message(FATAL_ERROR "Unsupported generator ${CMAKE_GENERATOR}. Hint: Try -G\"Unix Makefiles\"")
endif()