Only test MSRV with minimal versions

.github/workflows/rust.yml

@@ -37,8 +37,11 @@ jobs:
         run: cargo test --verbose
 
   verify-msrv:
-    runs-on: ubuntu-latest
-    name: verify minimum supported rust version (ubuntu)
+    strategy:
+      matrix:
+        os: [ubuntu-latest]
+    runs-on: ${{ matrix.os }}
+    name: verify minimum supported rust version without cache (takes longer, but caching produces unexpected behaviour)
     timeout-minutes: 30
 
     # we are using the `cargo-msrv` app
@@ -47,13 +50,27 @@ jobs:
     steps:
       - uses: actions/checkout@v2
 
-      - name: Install foresterre/cargo-msrv without cache (takes longer, but caching produces unexpected behaviour)
+      - name: Install foresterre/cargo-msrv
         run: cargo install cargo-msrv
 
-      - name: Verify the Rustc version declared in `cargo.toml` without cache (takes longer, but caching produces unexpected behaviour)
+      - uses: dtolnay/rust-toolchain@nightly
+      - name: Generate Cargo.lock with minimal-version dependencies
+        run: cargo -Zminimal-versions generate-lockfile
+
+      - name: Verify the Rustc version declared in `Cargo.toml`
+        run: cargo-msrv verify
+
+      - name: Verify MSRV with suggested `cargo update -p half --precise 2.1.0` workaround
         run: |
-          rm -f Cargo.lock
           cargo update
+          cargo update -p half --precise 2.1.0
+          cargo-msrv verify
+
+      - name: Verify MSRV with suggested `half = "=2.1.0"` workaround
+        run: |
+          cargo update
+          # Workaround should be available in any crate
+          sed -i 's/half = "2.1.0"/half = "=2.1.0"/' Cargo.toml
           cargo-msrv verify
 
   # github actions does not support big endian systems directly, but it does support QEMU.
@@ -94,16 +111,16 @@ jobs:
 
     steps:
     - uses: actions/checkout@v2
-    
+
     - name: Cache Cargo Dependencies
       uses: Swatinem/rust-cache@v1.3.0
-      
+
     - name: Add wasm32 Target
       run: rustup target add wasm32-unknown-unknown
-      
+
     - name: Build without default features
       run: cargo build --verbose --no-default-features --target wasm32-unknown-unknown
-      
+
     - name: Run tests without default features
       run: cargo test --verbose --no-default-features
 

README.md

@@ -31,7 +31,7 @@ Features include:
 > [!TIP]
 > MSRV Note: This crate is now on Rust `1.70.0`. If you want to use the
 > newest version of `exrs` with an older Rust version, you can still do that:
-> By specifying a version `half = "2.1.0"` in your project, the crate will work with Rust `1.59.0`.
+> By specifying a version `half = "=2.1.0"` in your project, or generating a lock file with minimal version dependencies (`cargo +nightly -Zminimal-versions generate-lockfile`), the crate will work with Rust `1.61.0`.
 
 This library has matured quite a bit, but should still be considered incomplete.
 For example, deep data and DWA compression algorithms are not supported yet.