报错内容
执行安装命令
sudo gem install -n /usr/local/bin cocoapods
报错如下
ERROR: While executing gem ... (Gem::FilePermissionError)
You don't have write permissions for the /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/gems/2.6.0 directory.
造孽啊！这种问题经常会出现在安装或想更新pod的iOSer。
分析原因：指定的ruby路径不对，应当使用更新版本的ruby
解决方案
执行安装命令 which -a ruby
如果终端机仅仅只存在一条路径，那么需要安装一个新的ruby。
/usr/bin/ruby
安装指令
重装指令brew reinstall ruby
安装指令brew install ruby
配置环境变量
echo 'export PATH="/usr/local/opt/ruby/bin:$PATH"' >> ~/.zshrc
更新环境变量
source ~/.zshrc
重新查询
再次使用which -a ruby查询，正确结果如下：
/usr/local/opt/ruby/bin/ruby
/usr/bin/ruby
执行Cocoapod安装指令
sudo gem install -n /usr/local/bin cocoapods
安装成功
......
Done installing documentation for nanaimo, colored2, claide, CFPropertyList, atomos, xcodeproj, ruby-macho, nap, molinillo, gh_inspector, fourflusher, escape, cocoapods-try, netrc, cocoapods-trunk, cocoapods-search, cocoapods-plugins, cocoapods-downloader, cocoapods-deintegrate, ffi, ethon, typhoeus, public_suffix, fuzzy_match, concurrent-ruby, httpclient, algoliasearch, addressable, tzinfo, i18n, activesupport, cocoapods-core, cocoapods after 19 seconds
33 gems installed
