如何在GitHub CI工作流中缓存Cargo包以加速构建？

我有一个使用Cargo包的GitHub CI，每次运行CI时构建该包大约需要6分钟。请问是否可以缓存二进制文件，以便下次运行时无需重复构建？以下是我的CI配置：

name: "Verify the specs of concrete tests using bulloak"

on: "workflow_call"

jobs:
  bulloak-check:
    runs-on: "ubuntu-latest"
    steps:
      - name: "Check out the repo"
        uses: "actions/checkout@v4"

      - name: "Install Rust"
        uses: "actions-rs/toolchain@v1"
        with:
          toolchain: "stable"

      - name: "Install bulloak or use the cached version"
        run: "cargo install bulloak"

      - name: "Verify the concrete tests"
        run: "bulloak check test/integration/concrete/**/**.tree --skip-modifiers"

      - name: "Bulloak summary"
        run: |
          echo "## Bulloak result" >> $GITHUB_STEP_SUMMARY
          echo "✅ Passed" >> $GITHUB_STEP_SUMMARY

可以通过GitHub Actions的缓存功能缓存cargo install生成的二进制文件，直接跳过重复构建步骤，大幅节省时间。修改后的CI配置如下：

name: "Verify the specs of concrete tests using bulloak"

on: "workflow_call"

jobs:
  bulloak-check:
    runs-on: "ubuntu-latest"
    steps:
      - name: "Check out the repo"
        uses: "actions/checkout@v4"

      - name: "Install Rust"
        uses: "actions-rs/toolchain@v1"
        with:
          toolchain: "stable"

      - name: "Cache bulloak binary"
        id: cache-bulloak
        uses: actions/cache@v3
        with:
          path: ~/.cargo/bin/bulloak
          key: ${{ runner.os }}-bulloak-${{ hashFiles('~/.cargo/registry/index/**') }}
          restore-keys: |
            ${{ runner.os }}-bulloak-

      - name: "Install bulloak if not cached"
        if: steps.cache-bulloak.outputs.cache-hit != 'true'
        run: "cargo install bulloak"

      - name: "Verify the concrete tests"
        run: "bulloak check test/integration/concrete/**/**.tree --skip-modifiers"

      - name: "Bulloak summary"
        run: |
          echo "## Bulloak result" >> $GITHUB_STEP_SUMMARY
          echo "✅ Passed" >> $GITHUB_STEP_SUMMARY

关键改动说明 #

• 新增缓存步骤：用actions/cache工具缓存~/.cargo/bin/bulloak二进制文件，这是cargo install最终生成的可执行文件路径
• 缓存键设计：键值包含操作系统标识和Cargo索引的哈希值，确保当bulloak版本更新或依赖包变更时，自动触发重新安装，避免缓存过时
• 条件安装：只有当缓存未命中时，才执行cargo install bulloak，缓存命中时直接跳过这一步
• 回退缓存：restore-keys配置让GitHub Actions能匹配最近的缓存版本，进一步提高缓存命中率

如果后续想进一步优化，还可以缓存Cargo的registry目录（~/.cargo/registry）和target目录，但针对当前场景，直接缓存二进制文件已经能解决核心的6分钟构建耗时问题。

内容的提问来源于stack exchange，提问作者smol-ninja