If you're on MacOSX & use Laravel valet for managing your development environment. Then this issue might arouse when you try to upgrade your PHP version or even Laravel Valet. But there's an easy fix for that.
The error saying Unable to determine linked PHP in Brew.php might appear possibly due to either Valet is unable to locate to the PHP's symlink or symlink is pointing for the supported PHP version for valet.
Run the following commands to fix this issue out forever.
brew unlink php && brew link phpbrew services restart --allcomposer global updatevalet start
