ci: run MSRV checks with minimal dep versions

.github/workflows/CI.yml

@@ -6,21 +6,18 @@ on:
     - master
   pull_request: {}
 
+env:
+  MSRV: 1.49.0
+
 jobs:
-  check:
+  check-stable:
+    # Run `cargo check` first to ensure that the pushed code at least compiles.
     runs-on: ubuntu-latest
-    strategy:
-      # Disable fail-fast. If the test run for a particular Rust version fails,
-      # don't cancel the other test runs, so that we can determine whether a
-      # failure only occurs on a particular version.
-      fail-fast: false
-      matrix:
-        rust: [stable, 1.49.0]
     steps:
     - uses: actions/checkout@master
     - uses: actions-rs/toolchain@v1
       with:
-        toolchain: ${{ matrix.rust }}
+        toolchain: stable
         profile: minimal
         override: true
     - name: Check
@@ -43,6 +40,22 @@ jobs:
         RUSTDOCFLAGS: "-D rustdoc::broken_intra_doc_links"
       run: cargo doc --all-features --no-deps
 
+  check-msrv:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@master
+    - name: "install Rust ${{ env.MSRV }}"
+      uses: actions-rs/toolchain@v1
+      with:
+        toolchain: ${{ env.MSRV }}
+        profile: minimal
+    - name: install cargo-hack
+      uses: taiki-e/install-action@cargo-hack
+    - name: install cargo-minimal-versions
+      uses: taiki-e/install-action@cargo-minimal-versions
+    - name: Check
+      run: cargo minimal-versions check --all --all-targets --all-features
+
   cargo-hack:
     runs-on: ubuntu-latest
     steps:
@@ -51,9 +64,8 @@ jobs:
       with:
         toolchain: stable
         profile: minimal
-    - name: Install cargo-hack
-      run: |
-        curl -LsSf https://github.com/taiki-e/cargo-hack/releases/latest/download/cargo-hack-x86_64-unknown-linux-gnu.tar.gz | tar xzf - -C ~/.cargo/bin
+    - name: install cargo-hack
+      uses: taiki-e/install-action@cargo-hack
     - name: cargo hack check
       working-directory: ${{ matrix.subcrate }}
       run: cargo hack check --each-feature --no-dev-deps --workspace
@@ -68,10 +80,11 @@ jobs:
       # failure only occurs on a particular version.
       fail-fast: false
       matrix:
-        rust: [stable, beta, nightly, 1.49.0]
+        rust: [stable, beta, nightly]
     steps:
     - uses: actions/checkout@master
-    - uses: actions-rs/toolchain@v1
+    - name: "install Rust ${{ matrix.rust }}"
+      uses: actions-rs/toolchain@v1
       with:
         toolchain: ${{ matrix.rust }}
         profile: minimal
@@ -82,6 +95,23 @@ jobs:
         command: test
         args: --workspace --all-features
 
+  test-msrv:
+    needs: check
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@master
+    - name: "install Rust ${{ env.MSRV }}"
+      uses: actions-rs/toolchain@v1
+      with:
+        toolchain: ${{ env.MSRV }}
+        profile: minimal
+    - name: install cargo-hack
+      uses: taiki-e/install-action@cargo-hack
+    - name: install cargo-minimal-versions
+      uses: taiki-e/install-action@cargo-minimal-versions
+    - name: Run tests
+      run: cargo minimal-versions test --all --all-targets --all-features
+
   style:
     needs: check
     runs-on: ubuntu-latest