Contents

Xcode 16.4 Release Notes

Update your apps to use new features, and test your apps against API changes.

Overview

Xcode 16.4 includes SDKs for iOS 18.5, iPadOS 18.5, tvOS 18.5, watchOS 11.5, macOS Sequoia 15.5, and visionOS 2.5. The Xcode 16.4 release supports on-device debugging in iOS 15 and later, tvOS 15 and later, watchOS 7 and later, and visionOS. Xcode 16.4 requires a Mac running macOS Sequoia 15.3 through macOS Tahoe 26.1.

General

Resolved Issues

  • Fixed: Users may see excessive CPU utilization from diskimagesiod which reduces simulator performance, increasing boot time, process launch times, and test execution times. (146716769) (FB16818022)

Apple Clang Compiler

Resolved Issues

  • Fixed: The base template for std::char_traits is restored after being removed in Xcode 16.3; it is still deprecated and is going to be removed in a future release. Restoring the base template allows code that attempts to instantiate char_traits with types that are not provided by the Standard (for example, std::basic_string<long long> and similar) to still compile, giving it more time to transition. (149025504)

Device

New Features

  • The command devicectl diagnose now obtains a sysdiagnose from your Mac and all available devices by default. (104845318)

Instruments

Resolved Issues

  • Fixed: Improved error handling for the Processor Trace Instrument when targeting binary not signed with get-task-allow entitlement. (139032322)

Simulator

Resolved Issues

  • Fixed: NSURLSession was always timing out and failing in iOS 18.3 simulator runtimes. (147849952) (FB17006003)

Source Editor

Resolved Issues

  • Fixed: Some C++ headers were experiencing crashes in syntax highlighting and Quick Help. (148020379)

See Also

Xcode 16