 brew install tmux
Warning: You are using macOS 10.13.
We (and Apple) do not provide support for this old version.
You will encounter build failures with some formulae.
Please create pull requests instead of asking for help on Homebrew's GitHub,
Twitter or any other official channels. You are responsible for resolving
any issues you experience while you are running this
old version.

==> Downloading https://mirrors.aliyun.com/homebrew/homebrew-bottles/ca-certificates-2022-07-19_1.all.bottle.tar.gz
Already downloaded: /Users/xuyinglong/Library/Caches/Homebrew/downloads/ea6e0173c119bdb2b64b2421364a39b02ed107471f6d6f10bf75dafc183db553--ca-certificates-2022-####    public.host
07-19_1.all.bottle.tar.gz
==> Downloading https://github.com/JuliaStrings/utf8proc/archive/v2.7.0.tar.gz
Already downloaded: /Users/xuyinglong/Library/Caches/Homebrew/downloads/1b8888ee93fe8b17e66e444119eb953ece9f1a07abee08a21d50a7111ea929a8--v2.7.0.tar.gz
==> Downloading https://raw.githubusercontent.com/imomaliev/tmux-bash-completion/f5d53239f7658f8e8fbaf02535cc369009c436d6/completions/tmux

curl: (7) Failed to connect to raw.githubusercontent.com port 443: Connection refused
Error: tmux: Failed to download resource "tmux--completion"
Download failed: https://raw.githubusercontent.com/imomaliev/tmux-bash-completion/f5d53239f7658f8e8fbaf02535cc369009c436d6/completions/tmux