Do the easy thing while it works, and when it stops working, fix the problem.
Julia does the same thing, and from the Rust numbers on the article, Julia has about 1/7th the number of packages that Rust does[1] (95k/13k = 7.3).
It works fine, Julia has some heuristics to not re-download it too often.
But more importantly, there's a simple path to improve. The top Registry.toml [1] has a path to each package, and once donwloading everything proves unsustainable you can just download that one file and use it to download the rest as needed. I don't think this is a difficult problem.
Julia does the same thing, and from the Rust numbers on the article, Julia has about 1/7th the number of packages that Rust does[1] (95k/13k = 7.3).
It works fine, Julia has some heuristics to not re-download it too often.
But more importantly, there's a simple path to improve. The top Registry.toml [1] has a path to each package, and once donwloading everything proves unsustainable you can just download that one file and use it to download the rest as needed. I don't think this is a difficult problem.
[1] https://github.com/JuliaRegistries/General/blob/master/Regis...