How can I figure out which URL is being blocked by App Transport Security?

Question

I\'m upgrading an iOS app to iOS 9, and I have some URLs that are not secure, and I need a few exceptions to App Transport Security. I\'ve added the two that I know about, b

Answer 1

Accepted answer is correct but If you're doing this on Xamarin iOS, you will need to use;

Environment.SetEnvironmentVariable("CFNETWORK_DIAGNOSTICS", "3", EnvironmentVariableTarget.Process);

Also, if you're looking for the log file use something like Simulator manager to find the correct location easier (https://github.com/tue-savvy/SimulatorManager).