Check list before re-install Xcode Command Line Tool

Environment & Phenomena

• Mac Pro (Late 2013)
• macOS Catalina ver. 10.15.7
• Xcode ver. 12.1 (12A7403)

failed to xcodebuild.

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

Really installed?

check the path

/Library/Developer/CommandLineTools

Check Location

Xcode > Preference > Locations

For me, this setting was empty. and now it works.

$ xcodebuild -version
Xcode 12.1
Build version 12A7403

Still not work, then Re-Install

$ xcode-select --install

or

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

or download installer from Apple Developers