Add rust-version

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## 6.1.1 (UNRELEASED)
 
+- Show a helpful error message when trying to install Rustlings with a Rust version lower than the minimum one that Rustlings supports.
 - Run the final check of all exercises in parallel.
 - Small exercise improvements.
 - `dev check`: Check that all solutions are formatted with `rustfmt`.

Cargo.toml

@@ -16,6 +16,7 @@ authors = [
 repository = "https://github.com/rust-lang/rustlings"
 license = "MIT"
 edition = "2021" # On Update: Update the edition of the `rustfmt` command that checks the solutions.
+rust-version = "1.80"
 
 [workspace.dependencies]
 serde = { version = "1.0.204", features = ["derive"] }
@@ -29,6 +30,7 @@ authors.workspace = true
 repository.workspace = true
 license.workspace = true
 edition.workspace = true
+rust-version.workspace = true
 keywords = [
   "exercise",
   "learning",

README.md

@@ -17,7 +17,7 @@ It contains code examples and exercises similar to Rustlings, but online.
 
 ### Installing Rust
 
-Before installing Rustlings, you need to have _Rust installed_.
+Before installing Rustlings, you need to have the **latest version of Rust** installed.
 Visit [www.rust-lang.org/tools/install](https://www.rust-lang.org/tools/install) for further instructions on installing Rust.
 This will also install _Cargo_, Rust's package/project manager.
 

rustlings-macros/Cargo.toml

@@ -6,6 +6,7 @@ authors.workspace = true
 repository.workspace = true
 license.workspace = true
 edition.workspace = true
+rust-version.workspace = true
 include = [
   "/src/",
   "/info.toml",