The biggest problem is that distributions have their own build systems and cargo just doesn't fit in a variety of different ways (not to mention projects that p

The biggest problem is that distributions have their own build systems and cargo just doesn't fit in a variety of different ways (not to mention projects that pin nightly compilers). Distributions such as Fedora and openSUSE need to have a package for everything installed on the system (and everything required to build said packages). Now take into account the you can have multiple versions of the same library in a single rust project. While you could handle all of this on paper, automating it and putting it all into every distributon's build system is a very big task. Ruby has similar problems, NodeJS is even worse than Ruby in this respect but I believe that Rust might make this the hardest for distributions. Personally I've never liked cargo that much as a user either, but as someone who works on openSUSE and was thinking about packaging rust packages I decided against it. It's just far too difficult and I'm not convinced it's worth the effort, since it feels like people have forgotten the reason why distributions exist in the first place (to provide a cohesive experience and provide you seamless management of your software). Having a shiny new package manager for every language just makes life difficult for everyone involved.