This is simply the Cairo clock tutorial, bundled with a CMake file, based on the gtkmm CMake tutorial.
To run a debug build, simply cd into the main project directory (such that ./readme.md resolves to this file) and run:
mkdir build_debug && cd build_debug && cmake -DCMAKE_BUILD_TYPE=Debug ../ && make && ./src_dir/clock
(Note the existence of the directory build_debug/src_dir which results from building the source-code contained within src_dir)
See COPYING.md.