fix(build): Installation instructions for linter (#1546)

* fix(build): installation instructions for linter

Closes #1540

* fix: Update README

* fix(build): formatting on missing toolchain

Closes #1538

* chore: Update changelog

CHANGELOG.md

@@ -6,6 +6,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixed
+- Fix installation instructions for `ink_linting` - [#1546](https://github.com/paritytech/cargo-contract/pull/1546)
+
 ## [4.0.1]
 
 ### Fixed

README.md

@@ -42,10 +42,15 @@ Modern releases of gcc and clang, as well as Visual Studio 2019+ should work.
 
 -   Step 2: `cargo install --force --locked cargo-contract`.
 
--   Step 3: Install `dylint` for linting.
+-   Step 3: Install dependencies for linting.
 
     -   (MacOS) `brew install openssl`
-    -   `cargo install cargo-dylint dylint-link`.
+    -   ```
+        export TOOLCHAIN_VERSION=nightly-2023-12-28
+        rustup install $TOOLCHAIN_VERSION
+        rustup component add rust-src --toolchain $TOOLCHAIN_VERSION
+        rustup run $TOOLCHAIN_VERSION cargo install cargo-dylint dylint-link
+        ```
 
 -   Step 4: (**Optional**) Install [Docker Engine](https://docs.docker.com/engine/install)
     to be able to produce verifiable builds.

crates/build/src/lib.rs

@@ -628,17 +628,23 @@ fn check_dylint_requirements(_working_dir: Option<&Path>) -> Result<()> {
             String::from_utf8_lossy(&output.stdout).contains(linting::TOOLCHAIN_VERSION),
             format!(
                 "Toolchain `{0}` was not found!\n\
-                This specific version is required to provide additional source code analysis.\n\n
-                You can install it by executing `rustup install {0}`.",
+                This specific version is required to provide additional source code analysis.\n\n\
+                You can install it by executing:\n\
+                  rustup install {0}\n\
+                  rustup component add rust-src --toolchain {0}\n\
+                  rustup run {0} cargo install cargo-dylint dylint-link",
                 linting::TOOLCHAIN_VERSION,
             )
             .to_string()
             .bright_yellow());
     } else {
         anyhow::bail!(format!(
             "Toolchain `{0}` was not found!\n\
-            This specific version is required to provide additional source code analysis.\n\n
-            Install `rustup` according to https://rustup.rs/ and then run: `rustup install {0}`.",
+            This specific version is required to provide additional source code analysis.\n\n\
+            Install `rustup` according to https://rustup.rs/ and then run:\
+              rustup install {0}\n\
+              rustup component add rust-src --toolchain {0}\n\
+              rustup run {0} cargo install cargo-dylint dylint-link",
             linting::TOOLCHAIN_VERSION,
         )
         .to_string()