This article starts a new series of blog posts about “bug hunts”. In these articles, I will go through a recent bug in Brian (or one of its dependencies) and describe all the steps I used to find the source of the bug and how I fixed it. I will try to not only focus on the Brian-side of things, but also show some general tools like git bisect or “monkey patching” that can be helpful to find the source of these nasty critters (no actual bugs were harmed during the making of this blog post).