Imo just use something else. If your build system is really simple just write the Makefiles yourself. If the build system tho needs to be really complex I would use something like meson or scons (Having worked on some gigantic fully GNU make build systems it can get pretty out of hand).

This is all a personal preference thing but cmake in my experience is really non intuitive and a pain to debug. I know it works for a lot of people but I definitely prefer particularly like scons since its python I have a bit easier time understanding what's happening.

If you really need to use cmake, use a debugger like another user commented. There's also a GNU make debugger in case you need to debug makefiles

Did you know that there is a debugger in Jetbrains CLion (and I think VS as well) that allows you to step through your CMake scripts? As ridiculous as this may seem, actually it is really useful.

I mean, all cmake does is run some commands for you. You not understanding cmake errors (mostly) means you don't understand the errors given to you by the C/C++ compiler.