Homebrew 安装包失败 & 切换源 & 安装缓慢

受某篇队列相关的教程安利，它简单的写下了 brew install rabbitmq 就开始介绍知识。笔者信了它的邪，装此包时，从 23:00 一直到 1:30，其中切换了两个源才解决 brew update 慢的问题，切换了控制台的梯子代理才解决下下载一个 github 上的 280MB 的包非常慢的问题，过程中还遇到了 Error: Permission denied 让我上火的事情。

下面我们开始第一步

$ brew install rabbitmq
Updating Homebrew...
==> Installing dependencies for rabbitmq: [email protected], libpng, wxmac and erlang
==> Installing rabbitmq dependency: [email protected]
==> Downloading https://homebrew.bintray.com/bottles/[email protected]
==> Downloading from https://akamai.bintray.com/d7/d7f992ebfd78f80828051f6dc6a1a99aed405f86b0f39ea651fd0afeadd1b0f4?__gda__=exp=1575992421~hmac=b48a88a6d35b1220627bfad07c5a04984d66b
######################################################################## 100.0%
==> Pouring [email protected]
==> Caveats
A CA file has been bootstrapped using certificates from the system
keychain. To add additional certificates, place .pem files in
  /usr/local/etc/[email protected]/certs

and run
  /usr/local/opt/[email protected]/bin/c_rehash

[email protected] is keg-only, which means it was not symlinked into /usr/local,
because openssl/libressl is provided by macOS so don't link an incompatible version.

If you need to have [email protected] first in your PATH run:
  echo 'export PATH="/usr/local/opt/[email protected]/bin:$PATH"' >> ~/.bash_profile

For compilers to find [email protected] you may need to set:
  export LDFLAGS="-L/usr/local/opt/[email protected]/lib"
  export CPPFLAGS="-I/usr/local/opt/[email protected]/include"

For pkg-config to find [email protected] you may need to set:
  export PKG_CONFIG_PATH="/usr/local/opt/[email protected]/lib/pkgconfig"

==> Summary