GitHub Actions中Xcode构建耗时过长，如何缩短构建时间？

针对你的iOS构建流水线耗时过长的问题，结合现有配置，给出以下可落地的优化手段：

1. 启用现代构建系统 #

你的xcodebuild命令中指定了-UseModernBuildSystem=NO，而现代构建系统（默认启用）支持并行构建、增量编译优化，能大幅提升构建速度。建议移除该参数，或显式设置为YES：

xcodebuild -workspace ios/AwesomeProject.xcworkspace -scheme AwesomeProject archive -sdk iphoneos -configuration Debug -archivePath $PWD/AwesomeProject CODE_SIGNING_ALLOWED=NO

2. 移除不必要的clean操作 #

每次构建执行clean会删除所有编译产物，强制全量编译，这是耗时的核心原因之一。若没有特殊清理需求，直接移除clean命令，改用增量构建：

xcodebuild -workspace ios/AwesomeProject.xcworkspace -scheme AwesomeProject archive -sdk iphoneos -configuration Debug -archivePath $PWD/AwesomeProject CODE_SIGNING_ALLOWED=NO

如果确实需要清理（比如依赖变更场景），可将clean拆分为单独步骤，仅在特定触发条件下执行。

3. 优化Pod依赖安装 #

• 跳过Pod仓库更新：若无需每次构建同步Pod索引，在pod install时添加--no-repo-update参数，节省仓库同步时间：

  pod install --no-repo-update
  

• 缓存Pod依赖：用GitHub Actions缓存功能保存Pods目录和Podfile.lock，避免重复下载安装依赖。在Install pod dependencies步骤前添加：

  - name: Cache Pods
    uses: actions/cache@v3
    with:
      path: ios/Pods
      key: ${{ runner.os }}-pods-${{ hashFiles('ios/Podfile.lock') }}
      restore-keys: |
        ${{ runner.os }}-pods-
  

4. 缓存Node与Xcode构建产物 #

• 缓存Node依赖：缓存node_modules目录，避免每次npm ci重复下载依赖：

  - name: Cache Node Modules
    uses: actions/cache@v3
    with:
      path: node_modules
      key: ${{ runner.os }}-node-${{ hashFiles('package-lock.json') }}
      restore-keys: |
        ${{ runner.os }}-node-
  

• 缓存Xcode DerivedData：Xcode的DerivedData目录存储编译中间产物，缓存它可实现增量编译，大幅减少重复编译时间：

  - name: Cache Xcode DerivedData
    uses: actions/cache@v3
    with:
      path: ~/Library/Developer/Xcode/DerivedData
      key: ${{ runner.os }}-deriveddata-${{ hashFiles('ios/AwesomeProject.xcodeproj/project.pbxproj', 'ios/Podfile.lock') }}
      restore-keys: |
        ${{ runner.os }}-deriveddata-
  

5. 调整构建配置提升速度 #

• 改用Release配置：Debug配置默认关闭编译优化、保留大量调试信息，编译速度慢。若构建归档无需调试功能，改用Release配置：

  xcodebuild -workspace ios/AwesomeProject.xcworkspace -scheme AwesomeProject archive -sdk iphoneos -configuration Release -archivePath $PWD/AwesomeProject CODE_SIGNING_ALLOWED=NO
  

• 优化Debug配置：若必须使用Debug，可在Xcode项目设置中将Optimization Level设为Fastest, Smallest，平衡调试能力与编译速度。

6. 启用并行构建 #

在xcodebuild命令中添加-parallelizeTargets参数，利用GitHub Runner的多核CPU并行编译多个目标：

xcodebuild -workspace ios/AwesomeProject.xcworkspace -scheme AwesomeProject archive -sdk iphoneos -configuration Debug -parallelizeTargets -archivePath $PWD/AwesomeProject CODE_SIGNING_ALLOWED=NO

7. 优化压缩步骤 #

当前使用zip -r -9的高压缩级别会增加耗时，可降低压缩级别至-6，在压缩速度和文件大小间取平衡：

zip -r -6 AwesomeProject.xcarchive.zip $PWD/AwesomeProject.xcarchive/

优化后的完整工作流示例 #

name: iOS

on: [push, pull_request]

jobs:
  build:
    runs-on: macos-latest
    steps:
    - uses: actions/checkout@v4
    
    - name: Cache Node Modules
      uses: actions/cache@v3
      with:
        path: node_modules
        key: ${{ runner.os }}-node-${{ hashFiles('package-lock.json') }}
        restore-keys: |
          ${{ runner.os }}-node-
    
    - name: Use Node.js
      uses: actions/setup-node@v4
      with:
        node-version: 14.x
        
    - run: npm ci

    - run: xcode-select -p
    
    - name: Cache Pods
      uses: actions/cache@v3
      with:
        path: ios/Pods
        key: ${{ runner.os }}-pods-${{ hashFiles('ios/Podfile.lock') }}
        restore-keys: |
          ${{ runner.os }}-pods-
          
    - run: pod install --no-repo-update
      working-directory: ios
      name: Install pod dependencies

    - name: Cache Xcode DerivedData
      uses: actions/cache@v3
      with:
        path: ~/Library/Developer/Xcode/DerivedData
        key: ${{ runner.os }}-deriveddata-${{ hashFiles('ios/AwesomeProject.xcodeproj/project.pbxproj', 'ios/Podfile.lock') }}
        restore-keys: |
          ${{ runner.os }}-deriveddata-

    - name: Build iOS (debug)
      run: "xcodebuild -workspace ios/AwesomeProject.xcworkspace -scheme AwesomeProject archive -sdk iphoneos -configuration Debug -parallelizeTargets -archivePath $PWD/AwesomeProject CODE_SIGNING_ALLOWED=NO"

    - name: Compress .xcarchive
      run: zip -r -6 AwesomeProject.xcarchive.zip $PWD/AwesomeProject.xcarchive/

    - uses: actions/upload-artifact@v4
      with:
        name: ios-xarchive
        path: AwesomeProject.xcarchive.zip

内容的提问来源于stack exchange，提问作者Muhammad_Bilal