报错：curl: (7) Failed to connect to raw.githubusercontent.com port 443: Connection refused
原因：访问问题
解决：
（1）手动下载brew_install.rb
下载地址：https://download.csdn.net/download/u011439689/12982734
（2）执行命令安装
ruby /Users/你的用户名/存放路径/brew_install.rb结果：
bogon:~ ddd$ ruby /Users/ddd/Downloads/brew_install.rb ==> This script will install: /usr/local/bin/brew /usr/local/share/doc/homebrew /usr/local/share/man/man1/brew.1 /usr/local/share/zsh/site-functions/_brew /usr/local/etc/bash_completion.d/brew /usr/local/Homebrew ==> The following existing directories will be made group writable: /usr/local/share/man/man3 /usr/local/share/man/man5 。。。。。（省略若干行） Cloning into '/usr/local/Homebrew/Library/Taps/homebrew/homebrew-core'... error: RPC failed; curl 18 transfer closed with outstanding read data remaining fatal: The remote end hung up unexpectedly Error: Failure while executing; `git clone https://github.com/Homebrew/homebrew-core /usr/local/Homebrew/Library/Taps/homebrew/homebrew-core` exited with 128. Error: Failure while executing; `/usr/local/bin/brew tap homebrew/core` exited with 1. Failed during: /usr/local/bin/brew update --forceerror: RPC failed; curl 18 transfer closed with outstanding read data remaining fatal: The remote end hung up unexpectedly
方法：
（1）使用git命令增大缓存（单位是b，524288000B也就500M左右）
git config --global http.postBuffer 524288000（2）执行brew update
bogon:~ ddd$ brew update ==> Tapping homebrew/core Cloning into '/usr/local/Homebrew/Library/Taps/homebrew/homebrew-core'... remote: Enumerating objects: 209, done. remote: Counting objects: 100% (209/209), done. remote: Compressing objects: 100% (121/121), done. Receiving objects: 35% (289988/807898), 83.63 MiB | 45.00 KiB/s 。。。（省略若干行） Tapped 2 commands and 5302 formulae (5,583 files, 356.4MB). Already up-to-date.完成
bogon:~ ddd$ brew -v Homebrew 2.5.6 Homebrew/homebrew-core (git revision f2003f; last commit 2020-10-20)
