Enforced Nightly toolchain for test

.github/workflows/rust.yml

@@ -60,7 +60,7 @@ jobs:
 
           # Determines if the cache should be saved even when the workflow has failed.
           # default: "false"
-          cache-on-failure: "false"
+          cache-on-failure: "true"
 
           # Determines which crates are cached.
           # If `true` all crates will be cached, otherwise only dependent crates will be cached.
@@ -91,9 +91,14 @@ jobs:
     needs: build-env
 
     steps:
-      - name: Checkout repository
-        uses: actions/checkout@v2
+        - name: Checkout repository
+          uses: actions/checkout@v2
+        - uses: actions-rs/toolchain@v1
+          with:
+            toolchain: nightly
+            override: true
+            profile: minimal
 
-      - name: Perform Test
-        run: |
-          cargo +nightly test --release
+        - name: Perform Test
+          run: |
+            cargo +nightly test --release