Flutter iOS构建执行pod install时出现NoMethodError报错求助

问题描述 #

在搭载M2 Pro芯片的Mac上构建Flutter iOS应用时，执行pod install出现以下报错：

NoMethodError - undefined method `present?' for nil:NilClass
/Users/User/.rvm/rubies/ruby-2.7.0/lib/ruby/gems/2.7.0/gems/cocoapods-1.13.0/lib/cocoapods/installer/podfile_validator.rb:100:in `validate_conflicting_external_sources!'
/Users/User/.rvm/rubies/ruby-2.7.0/lib/ruby/gems/2.7.0/gems/cocoapods-1.13.0/lib/cocoapods/installer/podfile_validator.rb:85:in `block in validate_pod_directives'
/Users/User/.rvm/rubies/ruby-2.7.0/lib/ruby/gems/2.7.0/gems/cocoapods-1.13.0/lib/cocoapods/installer/podfile_validator.rb:84:in `each'
/Users/User/.rvm/rubies/ruby-2.7.0/lib/ruby/gems/2.7.0/gems/cocoapods-1.13.0/lib/cocoapods/installer/podfile_validator.rb:84:in `validate_pod_directives'
/Users/User/.rvm/rubies/ruby-2.7.0/lib/ruby/gems/2.7.0/gems/cocoapods-1.13.0/lib/cocoapods/installer/podfile_validator.rb:40:in `validate'
/Users/User/.rvm/rubies/ruby-2.7.0/lib/ruby/gems/2.7.0/gems/cocoapods-1.13.0/lib/cocoapods/installer/analyzer.rb:225:in `validate_podfile!'
/Users/User/.rvm/rubies/ruby-2.7.0/lib/ruby/gems/2.7.0/gems/cocoapods-1.13.0/lib/cocoapods/installer/analyzer.rb:104:in `analyze'
/Users/User/.rvm/rubies/ruby-2.7.0/lib/ruby/gems/2.7.0/gems/cocoapods-1.13.0/lib/cocoapods/installer.rb:422:in `analyze'
/Users/User/.rvm/rubies/ruby-2.7.0/lib/ruby/gems/2.7.0/gems/cocoapods-1.13.0/lib/cocoapods/installer.rb:244:in `block in resolve_dependencies'
/Users/User/.rvm/rubies/ruby-2.7.0/lib/ruby/gems/2.7.0/gems/cocoapods-1.13.0/lib/cocoapods/user_interface.rb:64:in `section'
/Users/User/.rvm/rubies/ruby-2.7.0/lib/ruby/gems/2.7.0/gems/cocoapods-1.13.0/lib/cocoapods/installer.rb:243:in `resolve_dependencies'
/Users/User/.rvm/rubies/ruby-2.7.0/lib/ruby/gems/2.7.0/gems/cocoapods-1.13.0/lib/cocoapods/installer.rb:162:in `install!'
/Users/User/.rvm/rubies/ruby-2.7.0/lib/ruby/gems/2.7.0/gems/cocoapods-1.13.0/lib/cocoapods/command/install.rb:52:in `run'
/Users/User/.rvm/rubies/ruby-2.7.0/lib/ruby/gems/2.7.0/gems/claide-1.1.0/lib/claide/command.rb:334:in `run'
/Users/User/.rvm/rubies/ruby-2.7.0/lib/ruby/gems/2.7.0/gems/cocoapods-1.13.0/lib/cocoapods/command.rb:52:in `run'
/Users/User/.rvm/rubies/ruby-2.7.0/lib/ruby/gems/2.7.0/gems/cocoapods-1.13.0/bin/pod:55:in `<top (required)>'
/Users/User/.rvm/rubies/ruby-2.7.0/bin/pod:25:in `load'
/Users/User/.rvm/rubies/ruby-2.7.0/bin/pod:25:in `<main>'
/Users/User/.rvm/gems/ruby-2.7.0/bin/ruby_executable_hooks:22:in `eval'
/Users/User/.rvm/gems/ruby-2.7.0/bin/ruby_executable_hooks:22:in `<main>'

默认Flutter计数器应用可正常运行，已尝试以下方案但未解决：

• 执行flutter clean和flutter pub get
• 执行sudo arch -x86_64 gem install ffi
• 进入ios目录执行arch -x86_64 pod install
• 进入ios目录执行pod install --repo-update

解决方案 #

方案1：降级ActiveSupport版本 #

报错关联ActiveSupport 7.1.0的兼容性问题，执行以下命令降级到7.0.8：

gem uninstall activesupport
gem install activesupport -v 7.0.8

之后重新进入ios目录执行pod install。

方案2：升级CocoaPods版本 #

当前使用的CocoaPods 1.13.0存在该bug，升级到最新稳定版本：

gem update cocoapods

升级完成后清理缓存并重新安装：

pod cache clean --all
cd ios && pod install

方案3：切换Ruby环境 #

RVM管理的Ruby环境可能存在兼容性问题，尝试切换到系统Ruby：

1. 临时禁用RVM：rvm use system
2. 重新安装CocoaPods：sudo gem install cocoapods
3. 进入ios目录执行pod install

如果需要长期管理Ruby版本，建议使用rbenv替代RVM。

方案4：检查Podfile配置 #

报错出现在验证冲突外部源的步骤，检查ios目录下的Podfile，确保所有依赖的外部源配置完整，没有缺失git、path等关键字段，避免类似以下不完整的配置：

pod 'SomePod', :git => nil

内容的提问来源于stack exchange，提问作者Alex M