[cmake] CMake: Print out all accessible variables in a script

I'm wondering if there is a way to print out all accessible variables in CMake. I'm not interested in the CMake variables - as in the --help-variables option. I'm talking about my variables that I defined, or the variables defined by included scripts.

I'm currently including:

INCLUDE (${CMAKE_ROOT}/Modules/CMakeBackwardCompatibilityCXX.cmake)

And I was hoping that I could just print out all the variables that are here, instead of having to go through all the files and read what was available - I may find some variables I didn't know about that may be useful. It would be good to aid learning & discovery. It is strictly for debugging/development.

This is similar to the question in Print all local variables accessible to the current scope in Lua, but for CMake!

Has anyone done this?