[Kelteseth]

You should not do this:

> add_subdirectory(vendor/machineid)

> include_directories(vendor/machineid/include)

Every cmake library should expose the code they choose to expose. For example, if you have a library you should do this, inside the library

target_include_directories( ${PROJECT_NAME} PUBLIC inc/public/ PRIVATE src/)

Ideally, you even put another subfolder in the PUBLIC subfolder that contains the name of the library, so that when you include it, it looks like this:

#include "MyLibrary/Util.h"