I solved this problem by entering
Xcode > Preferences > Locations
And assigning the Command Line Tools
This is in Xcode Version 7.2 beta (7C46t)
In Xcode, open the Xcode menu at the top, then select Preferences…, and then select the Locations tab.
In Terminal, try this.
sudo xcode-select -s /Applications/Xcode.app
/Applications/Xcode.app is your Xcode.app path.
if U still get error in terminal.
try sudo xcodebuild -license to agree license.
sudo xcodebuild -license