ci: Turn on sccache for Rust (#2121)

.github/actions/rust/action.yml

@@ -33,6 +33,20 @@ runs:
         components: ${{ inputs.components }}
         targets: ${{ inputs.targets }}
 
+    - name: Use sccache
+      uses: mozilla-actions/sccache-action@2e7f9ec7921547d4b46598398ca573513895d0bd # v0.0.4
+
+    - name: Enable sscache
+      shell: bash
+      run: |
+        echo "CMAKE_C_COMPILER_LAUNCHER=sccache" >> "$GITHUB_ENV"
+        echo "CMAKE_CXX_COMPILER_LAUNCHER=sccache" >> "$GITHUB_ENV"
+        if [ "$GITHUB_WORKFLOW" ]; then
+          echo "SCCACHE_GHA_ENABLED=true" >> "$GITHUB_ENV"
+        fi
+        echo "RUSTC_WRAPPER=sccache" >> "$GITHUB_ENV"
+        echo "CARGO_INCREMENTAL=0" >> "$GITHUB_ENV"
+
     - name: Set up MSVC (Windows)
       if: runner.os == 'Windows'
       uses: ilammy/msvc-dev-cmd@v1
@@ -58,28 +72,3 @@ runs:
       env:
         GITHUB_TOKEN: ${{ inputs.token }}
       run: cargo +${{ inputs.version }} quickinstall $(echo ${{ inputs.tools }} | tr -d ",")
-
-    # sccache slows CI down, so we leave it disabled.
-    # Leaving the steps below commented out, so we can re-evaluate enabling it later.
-    # - name: Use sccache
-    #   uses: mozilla-actions/sccache-action@2e7f9ec7921547d4b46598398ca573513895d0bd # v0.0.4
-
-    # - name: Enable sscache
-    #   shell: bash
-    #   run: |
-    #     if [ "${{ runner.os }}" = "Windows" ]; then
-    #       echo "CC=sccache cl" >> "$GITHUB_ENV"
-    #       echo "CXX=sccache cl" >> "$GITHUB_ENV"
-    #     else
-    #       echo "CC=sccache cc" >> "$GITHUB_ENV"
-    #       echo "CXX=sccache c++" >> "$GITHUB_ENV"
-    #     fi
-    #     echo "SCCACHE_GHA_ENABLED=true" >> "$GITHUB_ENV"
-    #     echo "RUSTC_WRAPPER=sccache" >> "$GITHUB_ENV"
-    #     echo "CARGO_INCREMENTAL=0" >> "$GITHUB_ENV"
-
-    # Ditto for rust-cache.
-    # - name: Use Rust cache
-    #   uses: Swatinem/rust-cache@23bce251a8cd2ffc3c1075eaa2367cf899916d84 # v2.7.3
-    #   with:
-    #     cache-all-crates: "true"