I just played around with git-bug a bit ... I like it! It's kind of what I had in mind but I was going to create a BE compatibility mode. What it does do differently is stores the bugs in the reference tree so that no files are added to the project (well ... the ones that are added are in .git). Bugs and comments are committed and show up in the tree so I'm experimenting with how to run git log (aliases) without them showing up).