How to Manage the MSRV (Minimum Supported Rust Version)

Manage the Minimum Supported Rust Version (MSRV) by declaring it in your Cargo.toml file under the [package] section. This ensures your crate compiles with the specified version and prevents accidental upgrades to newer language features.

[package]
name = "your-crate-name"
version = "0.1.0"
rust-version = "1.70.0"

To verify your code adheres to this version, run cargo check using the specific toolchain: rustup run 1.70.0 cargo check.

The MSRV is the oldest version of Rust your software promises to work with. It matters because it protects users who haven't updated their tools yet, ensuring your code doesn't break on their machines. Think of it like a compatibility guarantee on a product box, promising it fits older models.