1. 现象

#brew update
Warning: No remote 'origin' in /opt/homebrew/Library/Taps/homebrew/homebrew-cask, skipping update!
Warning: No remote 'origin' in /opt/homebrew/Library/Taps/homebrew/homebrew-core, skipping update!
Warning: No remote 'origin' in /opt/homebrew/Library/Taps/homebrew/homebrew-services, skipping update!
Already up-to-date.

解决办法：

#brew doctor
Please note that these warnings are just used to help the Homebrew maintainers with debugging if you file an issue. If everything you use Homebrew for is working fine: please don't worry or file an issue; just ignore this. Thanks!Warning: Suspicious https://github.com/Homebrew/brew git origin remote found.
The current git origin is:https://mirrors.ustc.edu.cn/brew.gitWith a non-standard origin, Homebrew won't update properly.
You can solve this by setting the origin remote:git -C "/opt/homebrew" remote set-url origin https://github.com/Homebrew/brewWarning: Homebrew/homebrew-cask was not tapped properly! Run:rm -rf "/opt/homebrew/Library/Taps/homebrew/homebrew-cask"brew tap homebrew/caskWarning: Homebrew/homebrew-core was not tapped properly! Run:rm -rf "/opt/homebrew/Library/Taps/homebrew/homebrew-core"brew tap homebrew/core

根据提示输入

#rm -rf "/opt/homebrew/Library/Taps/homebrew/homebrew-cask"
#brew tap homebrew/cask==> Tapping homebrew/cask
Cloning into '/opt/homebrew/Library/Taps/homebrew/homebrew-cask'...
remote: Enumerating objects: 637993, done.
remote: Counting objects: 100% (12/12), done.
remote: Compressing objects: 100% (8/8), done.
remote: Total 637993 (delta 4), reused 9 (delta 4), pack-reused 637981
Receiving objects: 100% (637993/637993), 301.85 MiB | 7.85 MiB/s, done.
Resolving deltas: 100% (451622/451622), done.
Tapped 4019 casks (4,091 files, 322.3MB).#rm -rf "/opt/homebrew/Library/Taps/homebrew/homebrew-core"
#brew tap homebrew/core==> Tapping homebrew/core
Cloning into '/opt/homebrew/Library/Taps/homebrew/homebrew-core'...
remote: Enumerating objects: 1191036, done.
remote: Counting objects: 100% (7/7), done.
remote: Compressing objects: 100% (5/5), done.
remote: Total 1191036 (delta 2), reused 4 (delta 2), pack-reused 1191029
Receiving objects: 100% (1191036/1191036), 476.09 MiB | 10.04 MiB/s, done.
Resolving deltas: 100% (824978/824978), done.
Tapped 3 commands and 6066 formulae (6,405 files, 522.4MB).

执行brew update

#brew update  
Warning: No remote 'origin' in /opt/homebrew/Library/Taps/homebrew/homebrew-services, skipping update!
Already up-to-date.
#brew doctor                                                               
Your system is ready to brew.
#rm -rf "/opt/homebrew/Library/Taps/homebrew/homebrew-services" 
#brew tap homebrew/services    
==> Tapping homebrew/services
Cloning into '/opt/homebrew/Library/Taps/homebrew/homebrew-services'...
remote: Enumerating objects: 2000, done.
remote: Counting objects: 100% (509/509), done.
remote: Compressing objects: 100% (176/176), done.
remote: Total 2000 (delta 348), reused 441 (delta 325), pack-reused 1491
Receiving objects: 100% (2000/2000), 548.53 KiB | 1.33 MiB/s, done.
Resolving deltas: 100% (903/903), done.
Tapped 1 command (45 files, 700.5KB). #brew update     
Already up-to-date.

问题解决