Plan pattern for in-git build of a bash command

I keep having to dig around my various plans for good patterns so I thought I'd start to just catalog my latest here

I just made a quick fly-by contribution to the git-subtree project and I think the plan here is a good template for a habitat plan that will be embedded in a repo for a shell command. It determines its version number dynamically from the state of git's HEAD and installs a bash command locked into a habitat-provided bash version: