Issue: You may wish to override the default Xcode Active Developer Directory so build tools can target a legacy version or non-default version of Xcode. However, managed server users may not change the default Xcode active developer directory (we use Xcode version 9.4.1 as an example here) using the "sudo xcode-select --switch /Applications/Xcode9.4.1.app" command due to lack of administrator access.
Solution: To override the default Xcode Active Developer Directory, simply set the environment variable "DEVELOPER_DIR" in the Terminal app to the desirable Xcode version.
Temporarily set DEVELOPER_DIR to the available alternative Xcode version in the Applications folder. Or include the following in your bash profile ~/.bash_profile to overwrite default DEVELOPER_DIR to the desirable Xcode version:
Or, pass the variable directly to a build tool:
env DEVELOPER_DIR="/Applications/Xcode9.4.1.app" /usr/bin/xcodebuild
This will execute xcodebuild using an alternate developer directory (Xcode 9.4.1), rather than the xcodebuild tool that comes with the default Xcode.