Visual Studio Code for macOS error: xcrun: error: invalid active developer path

One day VS Code worked, the next day it didn't. The error was

xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools), missing xcrun at: /Library/Developer/CommandLineTools/usr/bin/xcrun

The problem was that macOS upgrades don't automatically update the XCode Developer Tools. To solve, execute the following shell command.

xcode-select --install

You don't need to restart VS Code for this to take effect.