想一如既往地在iOS Simulator上运行我的应用。当我单击运行时，出现错误，如下所示。该应用程序未进行重大更改，仅更改了一些文本。
以调试模式在iPhone 6上启动lib / main.dart ... 正在运行Pod安装... CocoaPods的输出： ... ... ... ```
### Error
```
NoMethodError - undefined method `size' for nil:NilClass
/Library/Ruby/Gems/2.6.0/gems/ruby-macho-1.4.0/lib/macho/macho_file.rb:455:in `populate_mach_header'
/Library/Ruby/Gems/2.6.0/gems/ruby-macho-1.4.0/lib/macho/macho_file.rb:233:in `populate_fields'
/Library/Ruby/Gems/2.6.0/gems/ruby-macho-1.4.0/lib/macho/macho_file.rb:55:in `initialize_from_bin'
/Library/Ruby/Gems/2.6.0/gems/ruby-macho-1.4.0/lib/macho/macho_file.rb:33:in `new_from_bin'
/Library/Ruby/Gems/2.6.0/gems/ruby-macho-1.4.0/lib/macho/fat_file.rb:365:in `block in populate_machos'
/Library/Ruby/Gems/2.6.0/gems/ruby-macho-1.4.0/lib/macho/fat_file.rb:364:in `each'
/Library/Ruby/Gems/2.6.0/gems/ruby-macho-1.4.0/lib/macho/fat_file.rb:364:in `populate_machos'
/Library/Ruby/Gems/2.6.0/gems/ruby-macho-1.4.0/lib/macho/fat_file.rb:156:in `populate_fields'
/Library/Ruby/Gems/2.6.0/gems/ruby-macho-1.4.0/lib/macho/fat_file.rb:95:in `initialize'
/Library/Ruby/Gems/2.6.0/gems/ruby-macho-1.4.0/lib/macho.rb:31:in `new'
/Library/Ruby/Gems/2.6.0/gems/ruby-macho-1.4.0/lib/macho.rb:31:in `open'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/xcode/linkage_analyzer.rb:16:in `dynamic_binary?'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/sandbox/file_accessor.rb:171:in `block in vendored_dynamic_frameworks'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/sandbox/file_accessor.rb:170:in `select'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/sandbox/file_accessor.rb:170:in `vendored_dynamic_frameworks'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/sandbox/file_accessor.rb:179:in `vendored_static_frameworks'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/target/build_settings.rb:679:in `each'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/target/build_settings.rb:679:in `flat_map'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/target/build_settings.rb:679:in `block in <class:PodTargetSettings>'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/target/build_settings.rb:114:in `block in define_build_settings_method'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/target/build_settings.rb:596:in `block in <class:PodTargetSettings>'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/target/build_settings.rb:114:in `block in define_build_settings_method'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/target/build_settings.rb:630:in `block in <class:PodTargetSettings>'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/target/build_settings.rb:114:in `block in define_build_settings_method'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/target/build_settings.rb:995:in `block in <class:PodTargetSettings>'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/target/build_settings.rb:114:in `block in define_build_settings_method'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/target/build_settings.rb:752:in `block in <class:PodTargetSettings>'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/target/build_settings.rb:114:in `block in define_build_settings_method'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/target/build_settings.rb:362:in `public_send'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/target/build_settings.rb:362:in `block in to_h'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/target/build_settings.rb:361:in `each'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/target/build_settings.rb:361:in `to_h'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/target/build_settings.rb:174:in `block in <class:BuildSettings>'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/target/build_settings.rb:544:in `block in <class:PodTargetSettings>'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/target/build_settings.rb:114:in `block in define_build_settings_method'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/installer/xcode/pods_project_generator/target_installer_helper.rb:16:in `update_changed_file'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/installer/xcode/pods_project_generator/pod_target_installer.rb:584:in `block in create_xcconfig_file'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/installer/xcode/pods_project_generator/pod_target_installer.rb:582:in `each'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/installer/xcode/pods_project_generator/pod_target_installer.rb:582:in `create_xcconfig_file'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/installer/xcode/pods_project_generator/pod_target_installer.rb:45:in `block in install!'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/user_interface.rb:145:in `message'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/installer/xcode/pods_project_generator/pod_target_installer.rb:34:in `install!'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/installer/xcode/pods_project_generator.rb:114:in `block in install_pod_targets'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/installer/xcode/pods_project_generator.rb:111:in `map'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/installer/xcode/pods_project_generator.rb:111:in `install_pod_targets'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/installer/xcode/single_pods_project_generator.rb:32:in `block in install_all_pod_targets'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/user_interface.rb:145:in `message'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/installer/xcode/single_pods_project_generator.rb:31:in `install_all_pod_targets'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/installer/xcode/single_pods_project_generator.rb:19:in `generate!'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/installer.rb:308:in `block in create_and_save_projects'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/user_interface.rb:64:in `section'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/installer.rb:303:in `create_and_save_projects'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/installer.rb:295:in `generate_pods_project'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/installer.rb:174:in `integrate'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/installer.rb:162:in `install!'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/command/install.rb:52:in `run'
/Library/Ruby/Gems/2.6.0/gems/claide-1.0.3/lib/claide/command.rb:334:in `run'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/command.rb:52:in `run'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/bin/pod:55:in `<top (required)>'
/usr/local/bin/pod:23:in `load'
/usr/local/bin/pod:23:in `<main>'
```
――― TEMPLATE END ――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――
[!] Oh no, an error occurred.
Search for existing GitHub issues similar to yours:
https://github.com/CocoaPods/CocoaPods/search?q=undefined+method+%60size%27+for+nil%3ANilClass&type=Issues
If none exists, create a ticket, with the template displayed above, on:
https://github.com/CocoaPods/CocoaPods/issues/new
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Don't forget to anonymize any private data!
Looking for related issues on cocoapods/cocoapods...
- NoMethodError - undefined method `size' for nil:NilClass
https://github.com/CocoaPods/CocoaPods/issues/8377 [closed] [14 comments]
a week ago
- NoMethodError - undefined method `each' for nil:NilClass
https://github.com/CocoaPods/CocoaPods/issues/9239 [closed] [5 comments]
2 weeks ago
- NoMethodError - undefined method `size' for nil:NilClass
https://github.com/CocoaPods/CocoaPods/issues/9484 [closed] [9 comments]
14 Apr 2020
and 4 more at:
https://github.com/cocoapods/cocoapods/search?q=undefined%20method%20%60size%27%20for%20nil&type=Issues&utf8=✓
运行pod安装时出错 在iPhone 6上启动应用程序时出错.```
有人知道，可能是什么问题？