It's possible that the .io cctld is going to go away [0]. Does crates.io have a backup plan at all? Does anyone know what problems it would end up causing?
I imagine the package registry having to move domains is going to cause a ton of problems.
Frankly, it's concerning to me that so much of the Rust ecosystem has chosen to standardize on shaky ccTLDs. The Indian Ocean Territory (.io) is a small island territory whose only inhabitants are a single military base, it is crazy to use that domain for something important. Serbia (.rs) is more stable, but they could still cut off access for non-Serbians if they wanted to.
[0] - https://en.wikipedia.org/wiki/.io#Phasing_Out
They are just iso country codes though, so it is just the luck that some have become so popular.
Some countries are pretty strict that their tlds must be local or at least provide translation in the regional language. The cook islands for instance have prime opportunity with .co.ck but they refuse the to let people take advantage