From 0a97f46d9cd67b60e49b28080932a42e2e80ee6a Mon Sep 17 00:00:00 2001
From: Hassan Abedi <cogitator.tech@gmail.com>
Date: Fri, 29 May 2026 15:11:37 +0200
Subject: [PATCH] Pin Rust version to `1.85.0`

---
 Cargo.toml                      | 1 +
 crates/README.md                | 2 +-
 crates/geomerge-demo/Cargo.toml | 1 +
 flake.nix                       | 4 ++--
 rust-toolchain.toml             | 3 +++
 5 files changed, 8 insertions(+), 3 deletions(-)
 create mode 100644 rust-toolchain.toml

diff --git a/Cargo.toml b/Cargo.toml
index bbfd8fc..12a24d8 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -5,6 +5,7 @@ resolver = "3"
 [workspace.package]
 edition = "2024"
 license = "MIT OR Apache-2.0"
+rust-version = "1.85.0"
 
 [workspace.lints.rust]
 unsafe_code = "forbid"
diff --git a/crates/README.md b/crates/README.md
index c47a2a9..bab6d4d 100644
--- a/crates/README.md
+++ b/crates/README.md
@@ -3,7 +3,7 @@
 Independent Rust app crates live in this directory.
 
 Each subdirectory should be a normal Cargo package with its own `Cargo.toml`.
-The repository root is a virtual workspace, so shared commands such as `make fmt-check`, `make clippy`, and `make test` run across all crates.
+The repository root is a virtual workspace, so shared commands such as `make format`, `make lint`, and `make test` run across all crates.
 
 Suggested shape:
 
diff --git a/crates/geomerge-demo/Cargo.toml b/crates/geomerge-demo/Cargo.toml
index b9336e7..2e9a343 100644
--- a/crates/geomerge-demo/Cargo.toml
+++ b/crates/geomerge-demo/Cargo.toml
@@ -3,6 +3,7 @@ name = "geomerge-demo"
 version = "0.1.0"
 edition.workspace = true
 license.workspace = true
+rust-version.workspace = true
 
 [lints]
 workspace = true
diff --git a/flake.nix b/flake.nix
index 507a81d..783e2cf 100644
--- a/flake.nix
+++ b/flake.nix
@@ -18,8 +18,8 @@
           overlays = [ rust-overlay.overlays.default ];
         };
 
-        # Edition 2024 requires Rust >= 1.85. Pin to a recent stable.
-        rustToolchain = pkgs.rust-bin.stable.latest.default.override {
+        # Pinned to match workspace.package.rust-version in Cargo.toml.
+        rustToolchain = pkgs.rust-bin.stable."1.85.0".default.override {
           extensions = [ "rust-src" "rust-analyzer" "clippy" "rustfmt" ];
         };
       in
diff --git a/rust-toolchain.toml b/rust-toolchain.toml
new file mode 100644
index 0000000..787a54a
--- /dev/null
+++ b/rust-toolchain.toml
@@ -0,0 +1,3 @@
+[toolchain]
+channel = "1.85.0"
+components = ["rustfmt", "clippy", "rust-analyzer"]