前言：继装完xcode-select 和command line 又报错
报错信息：
You are using macOS 11.4.
We do not provide support for this pre-release version.
You will encounter build failures with some formulae.
Please create pull requests instead of asking for help on Homebrew's GitHub,
Discourse, Twitter or IRC. You are responsible for resolving any issues you
experience while you are running this pre-release version
修复方式：执行以下这句命令
cd "$(brew --repo)" && git fetch && git reset --hard origin/master && brew update
可能是由于好多库没更新我的花费很长时间
使用命令等待很长时间后显示如下信息
image.png
OK ,解决。
