ci: Set up bencher (#1642)

* ci: Set up bencher

* Check out correct branch

* Use benchmark-action/github-action-benchmark

* Disable benchmark-action/github-action-benchmark until it's on the allowlist

* Enable?

* Fix?

.github/workflows/bench.yml

@@ -1,11 +1,12 @@
 name: Bench
 on:
   workflow_run:
-    workflows: ["CI"]
+    workflows: [CI]
     types: [completed]
 env:
   CARGO_TERM_COLOR: always
   RUST_BACKTRACE: 1
+  TOOLCHAIN: nightly
 
 jobs:
   bench:
@@ -16,8 +17,7 @@ jobs:
       - name: Install Rust
         uses: dtolnay/rust-toolchain@master
         with:
-          toolchain: stable
-          # components: rustfmt, clippy, llvm-tools-preview
+          toolchain: $TOOLCHAIN
 
       - name: Use sccache
         uses: mozilla-actions/[email protected]
@@ -27,17 +27,35 @@ jobs:
           echo "SCCACHE_GHA_ENABLED=true" >> "$GITHUB_ENV"
           echo "RUSTC_WRAPPER=sccache" >> "$GITHUB_ENV"
 
-      - name: Install dependencies (Linux)
+      - name: Install dependencies
         env:
           DEBIAN_FRONTEND: noninteractive
         run: |
-          sudo apt-get install -y --no-install-recommends gyp mercurial ninja-build lld
+          sudo apt-get install -y --no-install-recommends gyp mercurial ninja-build lld python-is-python3
           echo "RUSTFLAGS=-C link-arg=-fuse-ld=lld" >> "$GITHUB_ENV"
 
       - name: Checkout
         uses: actions/checkout@v4
+        with:
+          ref: ${{ github.event.workflow_run.head_branch }}
 
-      - name: Build
-        run: |
-          cargo bench --features ci,bench
+      - name: Benchmark
+        run: cargo +$TOOLCHAIN bench --features ci,bench | tee output.txt
+
+      - name: Download previous benchmark results
+        uses: actions/cache@v4
+        with:
+          path: ./cache
+          key: ${{ runner.os }}-benchmark
+
+      # - name: Store current benchmark results
+      #   uses: benchmark-action/github-action-benchmark@v1
+      #   with:
+      #     tool: 'cargo'
+      #     output-file-path: output.txt
+      #     external-data-json-path: ./cache/benchmark-data.json
+      #     fail-on-alert: true
+      #     github-token: ${{ secrets.GITHUB_TOKEN }}
+      #     comment-on-alert: true
+      #     summary-always: true