解决 Homebrew 下载更新极慢的问题

近期使用 Homebrew 去下载安装软件的时候总是卡在 update 阶段,时间非常久,难以忍受。记录一下解决方法,

症状

使用 Homebrew 安装软件的时候一直卡在 Update 阶段。同时发现从 github.com 下载文件也极度缓慢(几十 KB/s)。

问题定位

使用brew update --verbose观察 update 过程:

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brew update --verbose
Checking if we need to fetch /usr/local/Homebrew...
Checking if we need to fetch /usr/local/Homebrew/Library/Taps/caskroom/homebrew-fonts...
Fetching /usr/local/Homebrew...
Checking if we need to fetch /usr/local/Homebrew/Library/Taps/homebrew/homebrew-cask...
Checking if we need to fetch /usr/local/Homebrew/Library/Taps/homebrew/homebrew-core...
Fetching /usr/local/Homebrew/Library/Taps/homebrew/homebrew-cask...
Fetching /usr/local/Homebrew/Library/Taps/homebrew/homebrew-core...
remote: Enumerating objects: 337, done.
remote: Counting objects: 100% (337/337), done.
remote: Compressing objects: 100% (88/88), done.
remote: Total 298 (delta 221), reused 287 (delta 210), pack-reused 0
Receiving objects: 100% (298/298), 50.91 KiB | 39.00 KiB/s, done.
Resolving deltas: 100% (221/221), completed with 39 local objects.
From https://github.com/Homebrew/homebrew-core
65a45a9..583b7f1 master -> origin/master
remote: Enumerating objects: 179429, done.
remote: Counting objects: 100% (179429/179429), done.
remote: Compressing objects: 100% (56607/56607), done.
Receiving objects: 4% (7628/177189), 1.48 MiB | 8.00 KiB/s

发现 update 卡在从 github 仓库获取文件的过程。这个结果与手动从 github 下载文件慢的症状相互印证。

解决

由于问题主要是在国内网络环境 github 下载慢,因此尝试:

  1. 更换使用国内的 homebrew 镜像源;
  2. 使用代理访问 github.com。

更换 Homebrew 源

使用以下命令更换国内阿里云上的 homebrew 镜像:

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# 替换 brew.git:
cd "$(brew --repo)"
git remote set-url origin https://mirrors.aliyun.com/homebrew/brew.git
# 替换 homebrew-core.git:
cd "$(brew --repo)/Library/Taps/homebrew/homebrew-core"
git remote set-url origin https://mirrors.aliyun.com/homebrew/homebrew-core.git

# 替换 homebrew-bottles:
echo 'export HOMEBREW_BOTTLE_DOMAIN=https://mirrors.aliyun.com/homebrew/homebrew-bottles' >> ~/.zshrc
source ~/.zshrc

替换后,问题依旧,继续查看日志:

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brew update --verbose
Checking if we need to fetch /usr/local/Homebrew...
Checking if we need to fetch /usr/local/Homebrew/Library/Taps/caskroom/homebrew-fonts...
Fetching /usr/local/Homebrew...
Checking if we need to fetch /usr/local/Homebrew/Library/Taps/homebrew/homebrew-cask...
Checking if we need to fetch /usr/local/Homebrew/Library/Taps/homebrew/homebrew-core...
Fetching /usr/local/Homebrew/Library/Taps/homebrew/homebrew-core...
From https://mirrors.aliyun.com/homebrew/homebrew-core
+ 583b7f1...8435590 master -> origin/master (forced update)
Fetching /usr/local/Homebrew/Library/Taps/homebrew/homebrew-cask...
Fetching /usr/local/Homebrew/Library/Taps/caskroom/homebrew-fonts...
remote: Enumerating objects: 179429, done.
remote: Counting objects: 100% (179429/179429), done.
remote: Compressing objects: 100% (56607/56607), done.
Receiving objects: 6% (11170/177189), 2.16 MiB | 30.00 KiB/s

可以看到由于homebrew-cask的仓库依然指向了 Github,这个过程还是慢。阿里云的 镜像站 没有提供homebrew-cask,进一步搜索找到 USTC 镜像站,该站提供了homebrew-cask的源。使用上述同样的命令更换源:

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# 替换 homebrew-cask.git:
cd "$(brew --repo)"/Library/Taps/homebrew/homebrew-cask
git remote set-url origin https://mirrors.ustc.edu.cn/homebrew-cask.git

测试发现问题解决。

Note: Homebrew Bottles 源的更换方法详见 这里

官方源地址:
https://github.com/Homebrew/brew.git
https://github.com/Homebrew/homebrew-core.git
https://github.com/Homebrew/homebrew-cask

使用代理

家里的路由器已经配置好了 SS 代理,只要简单把github.com加入到黑名单强制走 proxy 就可以了。然而代理速度一般,效果不及上述方法。同时为了保证在其他网络环境下的效率,保留方法一所做的修改。