Dependency management is a solved problem in the C/C++ world.
It all should be done from within CMake using Hunter. They handle diamond dependencies correctly (everyone else just yolos it), they handle "package registry" correctly, ie git repos + hash verification. They handle tool chain files and forwarding of compilation flags correctly. I had a library building for like a dozen targets with it (including crazy stuff like iOS 9)
Solved problem is a strong statement. I've never heard of Hunter before. And as far as I can remember the most popular way of solving this is having a list of dependencies in a README somewhere so you can install them and their headers with your os/distro package manager
That's not a serious solution. You don't control dependency versions if you use a package manager and you can't build full static builds or full debug builds etc. Some targets don't have package managers (ex an embedded device)
It all should be done from within CMake using Hunter. They handle diamond dependencies correctly (everyone else just yolos it), they handle "package registry" correctly, ie git repos + hash verification. They handle tool chain files and forwarding of compilation flags correctly. I had a library building for like a dozen targets with it (including crazy stuff like iOS 9)