Python cryptography, Rust, and Gentoo

The fact that application developer using Rust don't particularly care about sticking to a lower version of Rust is indeed partly because the language is still evolving and gaining features, for instance async/await which was not available in the version of rustc originally shipped with Debian (the situation has since changed). But my point is that it also comes from the fact that it is *very* easy for a Rust developer using what is considered the standard way of developing in Rust to install and use multiple versions of a toolchain, and for most users *from their PoV* the version of Rust doesn't matter since either they compile from source and can thus be expected to use standard (for Rust) tooling, or they are using already-compiled binaries with no runtime dependency on the version of Rust.

Saying that maintenance costs, long-time support and combining multiple Rust projects in one system isn't considered by the Rust community is just plainly false. It's just a matter of perspective : they consider that rustc is just another build-time dependency and it's okay to require those that build to bump it, which in its face makes sense : you're already updating something in your system (the project itself), it shouldn't be a big bother to update something else.

I'm not saying this is the absolute right choice, as there clearly is a mismatch with how distros work, but things are not black and white.