Fix MSRV check target (#22)

Author: Finomnis

.github/workflows/ci.yml

@@ -134,10 +134,24 @@ jobs:
       - name: Install cargo-msrv
         run: cargo binstall --version 0.16.0-beta.22 --no-confirm cargo-msrv
 
+      # TODO: Revert to this, once https://github.com/foresterre/cargo-msrv/issues/936 is fixed.
+      # - name: Check with minimal versions
+      #   # To find out the current MSRV, remove the `rust-version` entry from `Cargo.toml` and run:
+      #   # run: cargo minimal-versions msrv --output-format json --all-features --target=thumbv7em-none-eabihf --log-target=stdout --log-level debug
+      #   run: cargo minimal-versions msrv --output-format json --all-features --target thumbv7em-none-eabihf verify
+
+      # WORKAROUND:
+      - name: Determine MSRV
+        run: echo "MSRV=$(cargo msrv show --output-format=minimal)" >> $GITHUB_ENV
+
+      - name: Show MSRV
+        run: echo $MSRV
+
+      - name: Install MSRV Rust version
+        run: rustup toolchain install $MSRV --target thumbv7em-none-eabihf
+
       - name: Check with minimal versions
-        # To find out the current MSRV, remove the `rust-version` entry from `Cargo.toml` and run:
-        # run: cargo minimal-versions msrv --output-format json --all-features --target=thumbv7em-none-eabihf --log-target=stdout --log-level debug
-        run: cargo minimal-versions msrv --output-format json --all-features --target thumbv7em-none-eabihf verify
+        run: cargo +${MSRV} minimal-versions check --target thumbv7em-none-eabihf --all-features
 
   semver:
     name: Semantic Versioning