Flutter Pod 安装失败 - '无效的 `Podfile` 文件没有将 nil 隐式转换为字符串

Question

我克隆了可穿戴项目 https://github.com/sbis04/flutter_os_wear

正在运行 pod 安装... CocoaPods 的输出： ↳

[!] Invalid `Podfile` file: no implicit conversion of nil into String.

 #  from /Volumes/Storage/Bottle/Wearables/flutter_os_wear/ios/Podfile:57
 #  -------------------------------------------
 #      unless File.exist?(copied_framework_path)
 >        FileUtils.cp_r(File.join(cached_framework_dir, 'Flutter.framework'), copied_flutter_dir)
 #      end
 #  -------------------------------------------

/Library/Ruby/Gems/2.6.0/gems/cocoapods-core-1.9.3/lib/cocoapods-core/podfile.rb:301:in `rescue in block in from_ruby'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-core-1.9.3/lib/cocoapods-core/podfile.rb:295:in `block in from_ruby'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-core-1.9.3/lib/cocoapods-core/podfile.rb:50:in `instance_eval'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-core-1.9.3/lib/cocoapods-core/podfile.rb:50:in `initialize'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-core-1.9.3/lib/cocoapods-core/podfile.rb:293:in `new'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-core-1.9.3/lib/cocoapods-core/podfile.rb:293:in `from_ruby'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-core-1.9.3/lib/cocoapods-core/podfile.rb:259:in `from_file'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/config.rb:200:in `podfile'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/command.rb:150:in `verify_podfile_exists!'
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.9.3/lib/cocoapods/command/install.rb:46: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>'

CocoaPods 的错误输出： ↳ 忽略 ffi-1.12.2，因为它的扩展没有构建。试试： gem pristine ffi --version 1.12.2

Answer 1

尝试取消注释 ${PROJECT}/ios/Podfile 中的这一行 platform :ios, '8.0' 并将其设置为更高版本（如 9.0）。