How can I set CG_CONTEXT_SHOW_BACKTRACE environmental variable?

Question

I have three buttons in my view. After setting the cornerRadus in the viewDidLoad() : button.layer.cornerRadius = 20 I get the following error message in the lo

Answer 1

On Xcode 7:

In case you still want the status bar is hidden, just change UIViewControllerBasedStatusBarAppearance in the Info.plist file into View controller-based status bar appearance. Don't forget to set it by NO