The open source Git project just released Git 2.48. Here is GitHub's look at some of the most interesting features and changes introduced since last time.
When "git fetch $remote" notices that refs/remotes/$remote/HEAD is
missing and discovers what branch the other side points with its
HEAD, refs/remotes/$remote/HEAD is updated to point to it.
Git has four build systems?? Meson seems overkill if you already have CMake too. The only thing it really adds is that it's nicer to write (CMake is somewhere between Bash and PHP in sanity), but if you have to write CMake anyway...
The liquor store presumably? Just submitting patches is a simple 12 step process. I can't imagine the development and review process is any easier.
I have implemented a Git client from scratch which involved quite a bit of reading the Git source code. It's not bad code but it's definitely the sort of code that would break in all sorts of unexpected ways if you changed something. I wouldn't volunteer my time their tbh.