Update your apps to use new features, and test your apps against API changes.
Xcode 10.3 includes SDKs for iOS 12.4, watchOS 5.3, macOS 10.14.6, and tvOS 12.4. Xcode 10.3 supports on-device debugging for iOS 8 and later, tvOS 9 and later, and watchOS 2 and later. Xcode 10.3 requires a Mac running macOS 10.14.3 or later.
Resolved an issue where running an app in iOS 12.2 or later under the Leaks instrument resulted in random numbers of false-positive leaks for every leak check after the first one in a given run. (48549361)