Atreides II

This issue seems to have been present for a long while and finally been merged into [cargo's main branch](https://github.com/rust-lang/cargo) just a week ago!! It was first tackled [here](https://github.com/rust-lang/cargo/issues/3931), later derived...

Hi! I think the issue here has to do with either instantiating a new Group object or appending it to a list (most likely the former) that one of these...