You usually have a Minimum Supported Rust Version (MSRV). Depending on crate this has to be set higher or lower. Of course you try to support old Rust compilers

You usually have a Minimum Supported Rust Version (MSRV). Depending on crate this has to be set higher or lower. Of course you try to support old Rust compilers as long as possible, but you will bump it up once in a while. Rust has become fairly stable now, especially since it's past the 1.0 release so stuff largely remains backwards compatible. You usually see MSRV requiring a compiler younger than 1-2 years, that's what I'm used to seeing.