All you would need is cargo compatibility, and a trusted namespace that kept up with the metadata of the current contents of crates.io, right?
edit: I really, really like rust, and love basically all of their choices about the language, but I can't stand the feeling that I'm being tricked into an ecosystem dependent on one of the worst behaved companies in the world, and I can't stand that a lot of rust projects smell like GPL-washing.
That being said, git is GPL and radicle is MIT, so it feels like the same thing, but Github also ain't git. I prefer MIT to MS; if radicle gets important enough and decides to rubpull, there will inevitably be a Free fork anyway.