Document MSRV and check it in CI

Author: robin-nitrokey

.github/workflows/ci.yml

@@ -85,3 +85,17 @@ jobs:
 
       - name: Build avr
         run: RUSTFLAGS="-C target-cpu=atmega328p" cargo +nightly build -Z build-std=core --target=avr-none --workspace --release
+
+  build-msrv:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+      - name: Install Rust toolchain for littlefs2-core
+        run: rustup override set 1.74
+      - name: Build littlefs2-core
+        # do not enable heapless09 and debug-error features as they require a newer Rust version
+        run: cargo build --package littlefs2-core --features heapless-bytes03,heapless-bytes04,heapless07,heapless08,serde
+      - name: Install Rust toolchain for littlefs2
+        run: rustup override set 1.87
+      - name: Build littlefs2
+        run: cargo build --package littlefs2 --all-features

CHANGELOG.md

@@ -7,7 +7,9 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## Unreleased
 
--
+### Changed
+
+- Documented the MSRV 1.87
 
 ## [v0.7.0](https://github.com/trussed-dev/littlefs2/releases/tag/0.7.0) - 2026-03-09
 

Cargo.toml

@@ -14,6 +14,7 @@ authors = ["Nicolas Stalder <n@stalder.io>", "Brandon Edens <brandonedens@gmail.
 readme = "README.md"
 categories = ["embedded", "filesystem", "no-std"]
 documentation = "https://docs.rs/littlefs2"
+rust-version = "1.87"
 
 edition.workspace = true
 license.workspace = true

core/CHANGELOG.md

@@ -7,7 +7,9 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## Unreleased
 
--
+### Changed
+
+- Documented the MSRV 1.74
 
 ## [v0.1.2](https://github.com/trussed-dev/littlefs2/releases/tag/core-0.1.2) - 2025-10-16
 

core/Cargo.toml

@@ -3,6 +3,7 @@ name = "littlefs2-core"
 version = "0.1.2"
 authors = ["The Trussed developers"]
 description = "Core types for the littlefs2 crate"
+rust-version = "1.74"
 
 edition.workspace = true
 license.workspace = true