I just spent a wonderful day tackling a single problem. I wanted the rbenv install plugin to update itself. I decided that was a single instance of a broader problem, having rbenv plugins update automagically.
If I wanted a rbenv plugin to update automagically, though, surely I also wanted rbenv to update itself? Surely! That makes sense, after all!
The end result is three github repositories. First, a tools repository that contains a couple of scripts I wrote to help me write rbenv plugins. It is here https://github.com/jamandbees/rbenvdevtools.
Second, a repository with a rbenv plugin that does a self update. https://github.com/jamandbees/rbenv-selfupdate
Third, a repository with a rbenv plugin that updates rbenv plugins. https://github.com/jamandbees/rbenv-plugins