ci: expand matrix to include older rusts

Author: demosdemon

.github/workflows/ci.yml

@@ -41,21 +41,40 @@ jobs:
         os:
           - ubuntu-latest
           - macos-latest
-          - windows-latest
+          # - windows-latest
         rust:
+          - "1.86"
+          - "1.87"
+          - "1.88"
+          - "1.89"
+          - "1.90"
           - stable
           - beta
           - nightly
+        rustc_bootstrap:
+          - "0"
+          - "1"
         exclude:
+          # bootstrap is only relevant for non-nightly toolchains
+          - os: ubuntu-latest
+            rust: nightly
+            rustc_bootstrap: "0"
+          - os: macos-latest
+            rust: nightly
+            rustc_bootstrap: "0"
+          # - os: windows-latest
+          #   rust: nightly
+          #   rustc_bootstrap: "0"
+        include:
           # Windows builds depend on an unstable feature: windows_process_exit_code_from
           # TODO: find a better way to handle this for windows without nightly
           - os: windows-latest
-            rust: stable
-          - os: windows-latest
-            rust: beta
+            rust: nightly
+            rustc_bootstrap: "1"
     runs-on: ${{ matrix.os }}
     env:
       RUSTFLAGS: "-D warnings"
+      RUSTC_BOOTSTRAP: ${{ matrix.rustc_bootstrap }}
     steps:
       - name: Checkout
         uses: actions/checkout@v4
@@ -65,7 +84,7 @@ jobs:
         with:
           toolchain: ${{ matrix.rust }}
           components: clippy
-          cache-shared-key: ${{ matrix.os }}-${{ matrix.rust }}
+          cache-shared-key: ${{ matrix.os }}-${{ matrix.rust }}${{ matrix.rust != 'nightly' && matrix.rustc_bootstrap == '1' && '-bootstrap' || '' }}
 
       - name: Fetch cargo dependencies
         run: cargo fetch --verbose --locked