Relationship with Compose.jl
Gadfly and Compose are tightly intertwined. As such, if you want to checkout the master branch of Gadfly to get the latest features and bug fixes, you'll likely also need to checkout Compose.
Moreover, if you're a contributor, you should probably tag releases of Gadfly and Compose simultaneously, and ideally submit a single PR to METADATA containing both. It is for this reason that neither uses attobot, as it has no mechanism to do this.