brew install watchman

警告

Warning: You are using macOS 14.
We do not provide support for this pre-release version.
It is expected behaviour that some formulae will fail to build in this pre-release version.
It is expected behaviour that Homebrew will be buggy and slow.
Do not create any issues about this on Homebrew's GitHub repositories.
Do not create any issues even if you think this message is unrelated.
Any opened issues will be immediately closed without response.
Do not ask for help from Homebrew or its maintainers on social media.
You may ask for help in Homebrew's discussions but are unlikely to receive a response.
Try to figure out the problem yourself and submit a fix as a pull request.
We will review it but may or may not accept it.

报错

Error: unknown or unsupported macOS version: :dunno

解决方案

执行更新命令

 cd "$(brew --repo)" && git fetch && git reset --hard origin/master && brew update
 
等待命令结束

No analytics have been recorded yet (nor will be during this `brew` run).

Already up-to-date.

重新安装watchman

brew install watchman
==> Fetching dependencies for watchman: icu4c, xz, lz4, zstd, boost, double-conversion, fmt, gflags, glog, ca-certificates, openssl@3, libevent, libsodium, snappy, folly, edencommon, fizz, wangle, fb303, mpdecimal, readline, sqlite and python@3.11

成功解决