I'm observing rust-bitcoin's struggles trying to stay conservative with minimum rust compiler version - as they want to support Debian Stable and generally have to be conservative about everything due to the nature of Bitcoin, and it makes me wonder if at some point we could introduce a concept of "last compiler version, we recommend all mature crates to still support".
After the codename for it is decided become visible as a target in
rustup and other places (CIs, tooling, etc.)
The goal here would be to give everyone maintainers some recommendation for how far back they should support legacy compiler releases, and packagers (linux distributions, people embedding rust compiler somewhere etc.) some idea how long they can expect given compiler version to keep compiling stable and mature code.
This could possibly be graded, so the most stable and mature crates can meet the demands of most conservative and slow moving ecosystems (like Debian Stable), while crates that just can't get there yet, can still aim at some intermediate step.