刚安装完Flutter执行pod install报错，信息如下
[!] Invalid `Podfile` file: undefined method `exists?' for File:Class.
# from /Users/zhujikai/Desktop/工作代码/flutter_module/.ios/Podfile:31
# -------------------------------------------
# use_frameworks!
> flutter_install_all_ios_pods File.dirname(File.realpath(__FILE__))
#
# -------------------------------------------
解决方法：
打开 /flutter/packages/flutter_tools/bin/podhelper.rb 文件
找到
return [] unless File.exists? file_path
替换成
return [] unless File.exist? file_path
