Specify the minimum supported Rust version

.github/workflows/ci.yml

@@ -55,6 +55,38 @@ jobs:
         cargo vet --version
         cargo vet --locked
 
+  msrv:
+    strategy:
+      matrix:
+        os:
+          - windows-2025
+          - ubuntu-24.04
+
+    runs-on: ${{ matrix.os }}
+
+    env:
+      EXPECTED_MSRV: "1.89"
+
+    steps:
+      - uses: actions/checkout@v6
+
+      - uses: actions/cache@v5
+        id: cache-cargo
+        with:
+          path: |
+            ~/.cargo/bin/
+            ~/.cargo/registry/index/
+            ~/.cargo/registry/cache/
+            ~/.cargo/git/db/
+            target/
+          key: ${{ runner.os }}-msrv-cargo-${{ hashFiles('**/Cargo.lock') }}
+
+      - name: Install Rust v${{ env.EXPECTED_MSRV }}
+        run: rustup install ${{ env.EXPECTED_MSRV }}
+
+      - name: Run cargo build using Rust v${{ env.EXPECTED_MSRV }}
+        run: cargo +${{ env.EXPECTED_MSRV }} build --workspace
+
   build:
     strategy:
       matrix:

Cargo.toml

@@ -6,6 +6,7 @@ authors.workspace = true
 repository.workspace = true
 license.workspace = true
 edition.workspace = true
+rust-version.workspace = true
 
 [dependencies]
 crc32fast = "1"
@@ -34,6 +35,7 @@ authors = ["Oliver Hamlet <oliver@ortham.net>"]
 repository = "https://github.com/loot/loot-condition-interpreter.git"
 license = "MIT"
 edition = "2021"
+rust-version = "1.89"
 
 # Deny some rustc lints that are allow-by-default.
 [workspace.lints.rust]

README.md

@@ -62,3 +62,7 @@ cmake ..
 cmake --build .
 ctest
 ```
+
+## Minimum supported Rust version
+
+The minimum supported Rust version is `1.89`. This may change at any time, but there is a CI job to check that it does not change unexpectedly.

ffi/Cargo.toml

@@ -5,6 +5,7 @@ authors.workspace = true
 repository.workspace = true
 license.workspace = true
 edition.workspace = true
+rust-version.workspace = true
 
 [dependencies]
 loot-condition-interpreter = { path = ".." }