今天我将macOS从10.13升级到了10.15（Catalina），然后执行git命令遇到了惊喜：
xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools), missing xcrun at: /Library/Developer/CommandLineTools/usr/bin/xcrun
解决办法：
xcode-select --install
参考：
https://stackoverflow.com/questions/58280652/git-doesnt-work-on-macos-catalina-xcrun-error-invalid-active-developer-path