MacOS下执行brew update发现报错

remote: Repository not found.
fatal: repository 'https://github.com/Homebrew/homebrew-boneyard/' not found
remote: Repository not found.
fatal: repository 'https://github.com/Homebrew/homebrew-dupes/' not found
remote: Repository not found.
fatal: repository 'https://github.com/Homebrew/homebrew-versions/' not found

解决办法：执行brew untap homebrew/boneyard