After upgrading macOS or after installing XCode you might bet a warning from Brew when executing brew doctor telling you that there is a new Command Line Tools release available:

Warning: A newer Command Line Tools release is available. Update them from Software Update in System Preferences or

But probably you already have the latest version so let’s try to get his fix.

So far I’ve found two solutions that worked fine to me twice.

Solution 1: Re-install Command Line Tools from the CLI

sudo rm -rf /Library/Developer/CommandLineTools
xcode-select --install

Solution 2: Re-install Command Line Tools from the Apple website

Download the latest version from here and install it manually opening the downloaded file.