我将macOS更新为High Sierra，之后所有pod命令（pod install，pod update）都停止工作。谷歌搜索后，我建议将你的红宝石从2.0更新到2.3.0。但是使用rvm命令面临以下错误。
Zubair-mac-mini:~ sdsol$ rvm install 2.3.0
Searching for binary rubies, this might take some time.
No binary rubies available for: osx/10.13/x86_64/ruby-2.3.0.
Continuing with compilation. Please read 'rvm help mount' to get more
information on binary rubies.
Checking requirements for osx.
Installing requirements for osx.
Updating system.........Failed to update Homebrew, follow instructions
here:
https://github.com/Homebrew/homebrew/wiki/Common-Issues
and make sure `brew update` works before continuing.
..
Error running 'requirements_osx_brew_update_system ruby-2.3.0',
please read /Users/sdsol/.rvm/log/1506680323_ruby-2.3.0/update_system.log
Requirements installation failed with status: 1.
Zubair-mac-mini:~ sdsol$
比我试图更新自制软件，但没有运气再次面临另一个问题
Zubair-mac-mini:~ sdsol$ brew update
Error: /usr/local must be writable!
非常感谢任何帮助。感谢