> This is also why 99% of rust documentation starts with telling you to install rust-up from out of repo third party sources: your local repository rust, no matter how new, is already out of date.

I don't see the problem. This seems like further evidence that distro package managers aren't the way forward. They can't keep up, they rarely have a sufficiently broad or up-to-date collection of packages, and when you integrate third party channels it can break other software ("run 'apt-get -f' to fix your dependencies" has never ever worked for me). Generally language-specific package managers work just fine.