From a1a59e8565fd051078008b01f0c96d76695e0e97 Mon Sep 17 00:00:00 2001
From: larry <26318510+larry0x@users.noreply.github.com>
Date: Fri, 17 Jul 2026 14:27:36 +0100
Subject: [PATCH] style: switch rustfmt from the nightly to the stable
 toolchain

Comment out the nine nightly-only options in rustfmt.toml (rather than
deleting them, so they are easy to reinstate) and drop the nightly
toolchain from the fmt CI job, the justfile recipe, the recommended
VSCode settings, and the README. The existing code already complies
with stable formatting, so no reformat is needed.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
---
 .github/workflows/rust.yml |  4 ++--
 .vscode/settings.json      |  3 ---
 README.md                  |  2 +-
 justfile                   |  2 +-
 rustfmt.toml               | 23 ++++++++++++++---------
 5 files changed, 18 insertions(+), 16 deletions(-)

diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index 62a4fce..9cfaf17 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -44,10 +44,10 @@ jobs:
           persist-credentials: false
 
       - name: Install toolchain
-        run: rustup toolchain install nightly --component rustfmt
+        run: rustup component add rustfmt
 
       - name: Run rustfmt checks
-        run: rustup run nightly cargo fmt --check --all
+        run: cargo fmt --check --all
 
   lint:
     name: Lint
diff --git a/.vscode/settings.json b/.vscode/settings.json
index e02d193..ffe31b9 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -14,9 +14,6 @@
     "**/Cargo.lock": true,
     ".git/": true
   },
-  "rust-analyzer.rustfmt.extraArgs": [
-    "+nightly"
-  ],
   "[json]": {
     "editor.defaultFormatter": "vscode.json-language-features",
     "editor.tabSize": 2
diff --git a/README.md b/README.md
index e3ae2bc..9b0ff57 100644
--- a/README.md
+++ b/README.md
@@ -15,7 +15,7 @@ Opinionated template for multi-crate Rust workspaces, with:
 
 The following software is expected to be installed and available in `PATH`:
 
-- [rustup][rustup] – Rust toolchain manager. Both the stable and nightly toolchains are used: nightly for `rustfmt` (`rustfmt.toml` contains unstable options), stable for everything else.
+- [rustup][rustup] – Rust toolchain manager. Only the stable toolchain is used.
 - [just][just] – Command runner. See the `justfile` for available recipes.
 - [taplo][taplo] – TOML formatter. Configured by `taplo.toml`.
 - [markdownlint-cli2][markdownlint-cli2] – Markdown linter. Configured by `.markdownlint.json`.
diff --git a/justfile b/justfile
index d63e8dd..c70f905 100644
--- a/justfile
+++ b/justfile
@@ -6,7 +6,7 @@ default:
 
 # Run rustfmt
 fmt:
-  cargo +nightly fmt --all
+  cargo fmt --all
 
 # Check whether the code compiles
 check:
diff --git a/rustfmt.toml b/rustfmt.toml
index 2fd133d..db038ee 100644
--- a/rustfmt.toml
+++ b/rustfmt.toml
@@ -1,17 +1,22 @@
 # Reference: https://rust-lang.github.io/rustfmt/
 
-condense_wildcard_suffixes     = true
-format_macro_bodies            = false
-format_macro_matchers          = false
-group_imports                  = "Preserve"
-imports_granularity            = "One"
 match_block_trailing_comma     = true
-normalize_comments             = true
-normalize_doc_attributes       = true
-overflow_delimited_expr        = true
-reorder_impl_items             = true
 single_line_if_else_max_width  = 0
 single_line_let_else_max_width = 0
 style_edition                  = "2024"
 use_field_init_shorthand       = true
 use_try_shorthand              = true
+
+# The following options are nightly-only. They are commented out because we
+# format with the stable toolchain; uncomment when any one of them becomes
+# available in stable.
+
+# condense_wildcard_suffixes = true
+# format_macro_bodies        = false
+# format_macro_matchers      = false
+# group_imports              = "Preserve"
+# imports_granularity        = "One"
+# normalize_comments         = true
+# normalize_doc_attributes   = true
+# overflow_delimited_expr    = true
+# reorder_impl_items         = true