Run the following command:

sudo xcode-select --reset

Why does this fix it?

As GitHub user @thowerton explains:

“The default path for Xcode when installing Xcode command line tools was incorrect. You can confirm if this is your issue by running $ xcodebuild , which will show an error like this if this is your issue:

xcode-select: error: tool ‘xcodebuild’ requires Xcode, but active developer directory ‘/Library/Developer/CommandLineTools’ is a command line tools instance”

The command above resets this.