Xcode 11 Beta 2 Release Notes

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


Xcode 11 includes SDKs for iOS 13, macOS Catalina 10.15, watchOS 6, and tvOS 13. Xcode 11 supports on-device debugging for iOS 8 and later, tvOS 9 and later, and watchOS 2 and later. Xcode 11 requires a Mac running macOS Mojave 10.14.4 or later.


New Features

  • Xcode 11 beta supports development with SwiftUI.

  • Xcode supports uploading apps from the Organizer window or from the command line with xcodebuild or xcrun altool. Application Loader is no longer included with Xcode. (29008875)

  • LaunchServices on macOS now respects the selected Xcode when launching Instruments, Simulator, and other developer tools embedded within Xcode. For example, when you double-click an Instruments trace in Finder, the version of Instruments for the selected Xcode launches. Change which Xcode is used with xcode-select from the command line. (6757601)

  • Editors can be added to any window without needing the Assistant Editor. Editors are added using the “Add Editor” button in the jump bar or the File > New > Editor command. Each editor can now be in one of three modes: “Editor Only”, “Editor and Assistant” or “Editor and Canvas”. The latter two modes automatically show relevant content when available. When using multiple editors, the View > Editor > Focus command can be used to temporarily expand the active editor to fill the entire window, hiding other editors. For source control support, the Code Review button in the Toolbar replaces the Comparison Editor. The “Show Authors” command is now available from the Source Editor’s Editor menu. The SCM Log is now in the Inspector Area. (43806898)

Known Issues

  • Xcode 11 beta doesn’t support working with SwiftUI in a project configured to use UIKit for Mac. (51201699)

  • When you launch Xcode on macOS 10.15 beta, the required packages installer might display erroneously. (51080815)

    Workaround: Continue through the installer.

  • The Environment Overrides button doesn’t appear in the debug bar for watchOS and iOS app extension targets until you pause the process. (51203640)

Resolved Issues

  • The Foundation integration for the Combine framework is now available. The following Foundation and Grand Central Dispatch integrations with Combine are available: KeyValueObserving, NotificationCenter, RunLoop, OperationQueue, Timer, URLSession, DispatchQueue, JSONEncoder, JSONDecoder, PropertyListEncoder, PropertyListDecoder, and the @Published property wrapper. (51241500)

  • Issue text is no longer light when using a light theme with a dark system appearance. (48230278)

Apple Clang Compiler

New Features

  • Clang now provides a mechanism for controlling exit-time destructor registration. You can disable these globally with the flag -fno-c++-static-destructors, or apply the attribute [[clang::no_destroy]] to disable the destructors of specific variables. The attribute [[clang::always_destroy]] was also added to enable destructors of specific variables when -fno-c++-static-destructors is used. (21734598)

  • As an extension, C++11 enums with fixed underlying types are now supported in all language modes. (43831380)

  • Deprecation warnings will be issued when standard library facilities that were deprecated in the active Standard version are used. (46881474)

  • Stack checking is on by default on all platforms to prevent memory corruptions. (25859140)

  • The machine code outliner is on by default under -Oz. It reduces code size by identifying identical code sequences across functions. Such sequences are encapsulated (“outlined”) in a single compiler generated function. Each original code sequence is replaced with a call to that outlined function. (46385499)

  • In order to improve performance and security the static linker (ld) now moves globals that are marked as constant into a new segment: __DATA_CONST. These globals may consist of compiler generated pointers that the dynamic linker (dyld) needs to fix up during load, but are otherwise constant such as vtables and explicitly declared constant pointers. Once dyld has finished loading the image it makes __DATA_CONST readonly. This change doesn’t impact well behaved code, but may break code that depends on undefined behavior such as using a type pun to write to a pointer that’s declared as const. (50898833)

    static int value1 = 0;                  // Stored in __DATA
    static int value2 = 0;                  // Stored in __DATA
    const int * const valuePtr = &value1;   // Stored in __DATA_CONST
    // ERROR: Attempting to store a value to a constant pointer
    (int *)valuePtr = &value2;

  • Clang now supports the C++17 <filesystem> library for iOS 13, macOS 10.15, watchOS 6, and tvOS 13. (50988273)

Known Issues

  • An if (@available()) check never succeeds when present in an object file or static archive built with Xcode 9 or Xcode 10, but linked by Xcode 11 into an app or framework that’s running on a iOS 13, macOS 10.15, watchOS 6, or tvOS 13. (51109405)

    Workaround: Rebuild the object file or static archive with Xcode 11.

  • When using manual retain-release, exceptions thrown from the following methods or any functions or methods they transitively call might not be caught: release, autorelease, retain, alloc, or allocWithZone. (50253394)

Resolved Issues

  • The <experimental/optional> and <experimental/variant> headers are removed. Use <optional> and <variant> from C++17 instead. (50175894)

  • Resolved a long compile-time issue in the loop-invariant code motion pass of the optimizer. (39648918)

Asset Catalog

New Features

  • Assets can now be cut, copied, pasted, and duplicated using the menu or keyboard shortcuts. (27107912)

Known Issues

  • Interface Builder’s image inspector crashes when the asset catalog has a symbol and bitmap image assets with the same name. (51279661)

  • New user-defined images added to the asset catalog don’t show up in the image view image combo box until you restart Xcode on macOS 10.15. (51090225)

  • Runtime lookup of NSDataAsset might return the wrong data when an asset has variants specified for iPad and UIKit for Mac. (49990047)

    Workaround: Use a different name for the UIKit for Mac asset.

Build System

New Features

  • Run script phases and custom build rules may declare and emit a dependencies file, in the Makefile-style .d format output used by some compilers and build tools. The build system checks the files listed for changes during subsequent builds when determining if the rule or phase should be executed. (49226986)

  • Projects may now use custom build rules to process header files (APPLY_RULES_IN_COPY_HEADERS). (48185100)

  • Custom build rules can now specify additional, static input files that are used during execution. These resolved input file paths are supplied to rule scripts using the SCRIPT_INPUT_FILE_# environment variables. (49645853)

  • Xcode removes some entries from the Info.plist file of a product at build time if the entries are not appropriate for the platform being built for, which is useful for targets which are configured to build for multiple platforms. This behavior can be disabled by setting the build setting DISABLE_INFOPLIST_PLATFORM_PROCESSING to YES, in which case the target must assume the responsibility of managing these entries appropriately. (47797497)

  • Custom build rules can now declare that they should run once per architecture (the default), or run only once across all architectures. This is useful for custom rules which are architecture-neutral, for example, code generation tools that generate files that don’t differ per architecture. (47716990)

  • XCFrameworks make it possible to bundle a binary framework or library for multiple platforms —including iOS devices, iOS simulators, and UIKit for Mac — into a single distributable .xcframework bundle that your developers can use within their own applications. An .xcframework bundle can be added to an Xcode target’s Link Libraries phase and Xcode uses the right platform’s version of the included framework or library at build time. Creation of XCFrameworks is supported from the command line using xcodebuild -create-xcframework. Frameworks or libraries bundled in an XCFramework should be built with the Build Libraries for Distribution build setting set to YES. (49948269)

Known Issues

  • Watch targets that override the Architectures build setting to just armv7k may fail to process in TestFlight and Xcode’s enterprise distribution workflow. (51104990)

    Workaround: Build the watchOS app with armv7k and arm64_32.

  • Incremental builds to may fail to codesign properly for non-source related changes to your project, such as resource file modifications, which can result in the app failing to launch. (41254808)

    Workaround: Change a source file within the same target to trigger the codesign process, or perform a clean build.

  • Updating your iOS app for Mac compatibility may show new error diagnostics stating that certain frameworks or functionality is not available on the Mac. If one of these diagnostics is shown erroneously, you can disable it by setting the VALIDATE_WORKSPACE build setting to NO. (50607174)

  • The new build system doesn’t evaluate a leading tilde (~) in paths in build settings to the user’s home directory. (41339901)

    Workaround: Use $(HOME) instead.

  • If a target enables RUN_CLANG_STATIC_ANALYZER, then single file processing commands — such as Compile, Preprocess, Show Assembly — won’t work correctly because they generate the static analyzer output file rather than the appropriate output. (43340227)

    Workaround: Disable RUN_CLANG_STATIC_ANALYZER in the target.

  • If the build of an app-hosted test target — where TEST_HOST is defined — fails, subsequent builds may fail when signing the app product because the test target is incomplete and unsigned when the initial signing of the app occurs. (43402096)

    Workaround: Perform a clean build. Or, manually delete the unsigned test bundle from inside the app target’s product and rebuild.

  • Targets which override the Architectures and Valid Architectures build settings for iOS may need to remove or conditionalize the overrides to build correctly for Mac when using UIKit for Mac. (51074742)

  • When using Xcode on macOS 10.15, some files — especially xib and storyboard files — might be copied rather than compiled, resulting in an incorrect build product. (49351105)

    Workaround: In the File Inspector for the file which is being copied, toggle the Type popup away from Default - <some type> then back to Default. This resets the file type in the project file to the correct type and enables the build system to match it to the correct tool to process it.

  • After closing and reopening a project, or when performing incremental builds using xcodebuild, diagnostics from prior builds regarding incompatible frameworks, app extensions, and code signing settings may be displayed without a description in the Issue Navigator and Build Log. (51131884)

    Workaround: Use the Product menu to Clean Build Folder, then build again.

  • When building for the first time users may get a popup stating that SimulatorTrampoline would like access to Desktop Files because ibtool running in simulator needs access to these files to compile storyboards. (51114450)

    Workaround: Allow access to the files in the prompt.

  • Some features that aren’t supported by the legacy build system are ignored instead of emitting an error. This includes use of build rule or script phase dependency files, input declarations for custom build rules, and the APPLY_RULES_IN_COPY_HEADERS build setting. (51318274)

Resolved Issues

  • By default, Xcode’s new build system doesn’t detect changes in directories declared as inputs to shell script build phases. Enabling the build setting ALLOW_RECURSIVE_SCRIPT_INPUTS causes it to do so. However, if any of the files inside such a directory are generated by a task that depends on the output of the script phase, then a dependency cycle error is emitted and must be resolved by restructuring the target. (41126633)

  • The build system no longer crashes when building some targets that use On Demand Resources. (49072702)

Command Line Tools

Known Issues

  • pip3 is unavailable using the default shell PATH. (50877974)

    Workaround: Use xcrun to find and execute pip3. For example: xcrun pip3.

  • Python 3 is unavailable in the Command Line Tools package. (51727440)

    Workaround: Install Xcode 11 and select it using xcode-select.

Core Data

New Features

  • There is now a checkbox that makes it possible for you to distinguish whether the default value of a string attribute should be nil or the empty string. When set, the default value is the empty string if no other default is specified. (26534406)

  • The Xcode 11 data model file format no longer writes out or preserves deprecated Sync Services information for entities or properties. (32524648)

  • The Core Data data model editor has added support for derived attributes when using the Xcode 11 data model file format and an appropriate deployment target. (45567066)

  • When creating an application using Core Data, there is a new checkbox to also enable CloudKit support for the data model’s default configuration. This can also be enabled for an existing data model using the new configuration inspector. When a data model configuration supports CloudKit, the data model editor performs additional validation to ensure the model conforms to the requirements for Core Data CloudKit support. (51126024)

Resolved Issues

  • Using the UUID attribute type, the URI attribute type, or the persistent history feature properly generates an error when used with a data model file format prior to the format used in Xcode 9. (50188371)


New Features

  • The graphical filter in the Size inspector for debugging view hierarchies identifies which attributes on the selected view are constrained. Selecting attributes in the filter narrows the displayed constraints to ones matching that attribute. Standard modifier keys such as Shift and Command can be used to expand the selection showing the union of constraints matching those attributes. (44864394)

  • You can now debug the view hierarchies of watchOS apps. (45173634)

  • You can now simulate network conditions and thermal states for a connected device from the Devices and Simulators window. (44608479)

  • The view debugger shows UIWindowScene instances in the debug navigator and canvas. (45378799)

  • View debugging can be disabled in the scheme options. (45928299)

  • The Size inspector for debugging view hierarchies has more details about constraints including a filter, hover highlighting in the editor, and better descriptions. (16153188)

  • The view debugger supports debugging iPad apps on Mac. (37507479)

  • The view debugger inspector shows contentTintColor for NSImageView and NSButton. (49506123)

  • The view debugger now shows the names of iOS named and system colors. (45162028)

  • The view debugger shows trait collection information. (45161975)

  • The view debugger shows the names of UIImage instances. (45327089)

  • The view debugger now shows symbol information, like baseline and midline. (49508874)

  • The debug bar appearance switcher supports changing between dark and light modes on iOS. (45161907)

  • The “Pause on issues” checkboxes in the Diagnostics tab of the Scheme Editor are replaced by regular breakpoints. You can use the Breakpoints Navigator to create a Runtime Issue Breakpoint. (31409112)

  • Override system settings like appearance, dynamic type, and accessibility options for the debugged process using Environment overrides, accessible from the debug bar. (45848655)

  • The debugger supports working with crash logs (.crash files). (48408310)

  • The debugger can debug tvOS Top Shelf extensions. (48869701)

  • Xcode can prefer using Wi-Fi to connect to a Watch when installing or debugging an app. (50313856)

  • The VoiceOver actions menu for breakpoints includes an action to jump to the corresponding line of code. (44941178)

  • When debugging views with constraints, double clicking a constraint in the size inspector selects that constraint in the editor and show information for the constraint in the inspector. (18842905)

Known Issues

  • Debugging symbols might be unavailable for Apple Watch. (26995636)

    Workaround: Verify that you have a working internet connection and that you’re signed into your Apple ID in Preferences > Accounts.

  • A preview debug session ends if the preview is no longer visible, including when stepping or view debugging. (50593619)

    Workaround: Ensure that the preview remains open by opening files in split mode or separate tabs. For example, hold down Option while clicking the Step Into or Debug View Hierarchy buttons to open them in separate editor splits.

  • You can’t debug on-device previews. (51183159)

    Workaround: Debug live previews on the canvas or debug the app on the device by directly deploying it there.

  • If the process is already started, adding a runtime issue breakpoint has no effect. (49433870)

    Workaround: Add the runtime issue breakpoint before running the process.

  • On macOS 10.15, dragging the process item in the Debug Navigator might crash Xcode. (48453949)

  • Debugging a watch app in a watchOS simulator might fail the first time the simulator boots. (50263836)

    Workaround: Wait until the watch simulator finishes booting, then start debugging it again.

  • App and thermal state tracks in the Energy Impact gauge might stop updating. (50968828)

    Workaround: Stop and rerun the app.

Resolved Issues

  • Items in the view debugger can be revealed in the Debug navigator from the context menu. (18598643)

  • Improved the formatting of Swift class names when debugging the view hierarchy. (39679411)

  • Fixed an issue where the debug console would display a page column guide. (49693398)

  • Breakpoints support the VoiceOver command to open the shortcut menu. (44940944)


  • Scripting language runtimes such as Python, Ruby, and Perl are included in macOS for compatibility with legacy software. In future versions of macOS, scripting language runtimes won’t be available by default, and may require you to install an additional package. If your software depends on scripting languages, it’s recommended that you bundle the runtime within the app. (49764202)

  • Use of Python 2.7 isn’t recommended. This version is included in macOS for compatibility with legacy software. Future versions of macOS won’t include Python 2.7. Instead, it’s recommended that you run python3 in Terminal. (51097165)

  • The Quartz Composer framework is deprecated. Starting in macOS 10.15, the Quartz Composer framework will be marked as deprecated and remain present for compatibility purposes. Transition to frameworks such as Core Image, SceneKit, or Metal if your app is using Quartz Composer. (50911608)

  • Command line tool support for Subversion — including svn, git-svn, and related commands — is no longer provided by Xcode. If you need Subversion or related command line tools, install the Command Line Tools package by running xcode-select --install. (50266910)


Known Issues

  • Building and running a watchOS app on a device might show a system spinner indefinitely. (51726238)

    Workaround: Reboot the device.

Resolved Issues

  • Resolved an issue that prevented running a watch app built with the thread sanitizer enabled on older versions of watchOS. (49288795)

  • Resolved an issue with half point frame differences caused by switching between Retina and non-Retina monitors. (20175879)


New Features

  • Tracks in Instruments can now be formed in hierarchies. They can now represent any engineering type and are created using Custom Instruments. (28615789)

  • Instruments now allows for copying multiple rows from a table at one time. (39326522)

  • Instruments allows for creating scopes for easier navigation within the trace document. (49022012)

  • <os-signpost-point-schema> is available in the Custom Instruments to match point events coming from os_signpost(_:dso:log:name:signpostID:). (50586708)

Known Issues

  • The selected track isn’t rendered in the Touch Bar area of Instruments. (50186374)

  • When profiling a standalone watchOS app, an iOS simulator is launched. (49788679)

Interface Builder

New Features

  • UIViewController instances now default to the Automatic modal presentation mode. Modal presentation segues can override this setting. (48129590)

  • Interface Builder supports Dark Mode on iOS. (45314199)

  • Interface Builder’s device bar lets you switch between the light and dark appearance for iOS apps. (45282451)

  • You can add SwiftUI hosting controllers, such as UIHostingController, to connect a storyboard controller flow to a hosting controller that manages a SwiftUI view hierarchy. You can populate the contents of a hosting controller in Interface Builder by providing a custom subclass that programmatically sets the rootView of the controller. (46039344)

    You can also set the root view of a UIHostingController or NSHostingController using a Segue Action.

  • The object library now matches the selected system-wide appearance. (50874168)

  • The NSStackView inspector now allows configuring negative spacing. (49012055)

  • NSSwitch is available when running on macOS 10.15. (47566686)

  • Cells in a UITableView can now self size with Auto Layout constrained views in the canvas. To opt into the behavior for existing table views, enable “Automatic” for the table view estimated item size, and “Automatic” for cell’s height in the Size inspector. (35735970)

  • NSView and UIView have a layout mode option in the Size inspector to explicitly opt into “translates autoresizing mask into constraints”. The default setting is “Automatic”, which is the existing behavior. “Automatic” implies that “translate autoresizing mask into constraints” is off when a view affect by constraints in the storyboard or XIB, but on if unconstrained. (37352354)

  • Improved the reliability of Auto Layout constraint generation with “Add Missing Constraints”. (43694622)

  • The contents of a UIScrollView are scrollable within the canvas, once its subviews are fully constrained with Auto Layout constraints. (44727961)

  • Cells in a UICollectionView can now self size with Auto Layout constrained views in the canvas. To opt into the behavior for existing collection views, enable “Automatic” for the collection view’s estimated size, and “Automatic” for cell’s size from the Size inspector.
If deploying before iOS 13, you can activate self sizing collection view cells by calling performBatchUpdates(_:completion:) during viewDidLoad(). (45617083)

  • In inspector font popovers, the Family popup now renders menu items as a preview of the applicable font. (31484154)

  • Update Frames can now be performed document-wide for misplaced frames, without selecting a view. (22076710)

  • Content and Frame Layout guides are supported for UIScrollView and can be enabled in the Size inspector for more control over your scrollable content. (29711618)

  • Interface Builder supports the new Apple TV tab bar style. (47598643)

  • The new WKInterfaceTextField interface element is available for watchOS. (45754186)

  • The canvas supports customizing iPad app interfaces for Mac. (37797710)

  • SF Symbols are available in image inspector properties. (47532055)

  • The UIImageView inspector includes support for configuring symbols. (47797500)

  • A view controller method annotated with the new @IBSegueAction attribute can be used to create a segue’s destination view controller in code, using a custom initializer with any required values. This makes it possible to use view controllers with non-optional initialization requirements in storyboards. Create a connection from a segue to an @IBSegueAction method on its source view controller. On new OS versions that support Segue Actions, that method will be called and the value it returns will be the destinationViewController of the segue object passed to prepare(for:sender:). Multiple @IBSegueAction methods may be defined on a single source view controller, which can alleviate the need to check segue identifier strings in prepare(for:sender:). (47091566)

    An IBSegueAction method takes up to three parameters: a coder, the sender, and the segue’s identifier. The first parameter is required, and the other parameters can be omitted from your method’s signature if desired. The NSCoder must be passed through to the destination view controller’s initializer, to ensure it’s customized with values configured in storyboard. The method returns a view controller that matches the destination controller type defined in the storyboard, or nil to cause a destination controller to be initialized with the standard init(coder:) method. If you know you don’t need to return nil, the return type can be non-optional.

    In Swift, add the @IBSegueAction attribute:

    func makeDogController(coder: NSCoder, sender: Any?, segueIdentifier: String?) -> ViewController? {
            coder: coder,
            petName:  self.selectedPetName, type: .dog

    In Objective-C, add IBSegueAction in front of the return type:

    - (IBSegueAction ViewController *)makeDogController:(NSCoder *)coder
          segueIdentifier:(NSString *)segueIdentifier
       return [PetController initWithCoder:coder

Known Issues

  • Storyboards and XIB files created with Xcode 11 that contain Quaternary System Fill Color, Secondary System Fill Color, Tertiary System Fill Color, or System Fill Color crash previous versions of Xcode when opened. (51233884)

  • When viewing an iPad storyboard with the Mac device selected in the device bar, custom fonts added by the project don’t render. (48528374)

  • Xcode crashes when you open a XIB or storyboard file with a custom view that is tagged as IBDesignable if that project contains Swift packages. (50551974)

  • UIKit menus configured in Interface Builder are available at runtime on macOS, but not on iOS. (51077651)

  • ARView objects in Apple TV storyboards crash Interface Builder rendering. (50971800)

  • The iOS status bar is not displayed in the Interface Builder canvas. (48639919)

  • View controller scenes that contain menu commands created with Xcode 11 cause the app to crash when running on iOS 12. (50871098)

  • Storyboards and XIB files in iOS and tvOS template projects created with Xcode 11 need to be saved with Xcode 11 at least once before opening them in previous versions of Xcode. (51230799)

  • UILabel, UITextField, and UITextView instances with alignment set to “center” or “right” in Interface Builder have the wrong alignment when designing for or running on macOS. (50062524)

    Workaround: Reapply the desired alignment in awakeFromNib().

  • If a symbol has a light and dark mode representation, the dark mode representation isn’t picked up in the storyboard. (50354204)

  • The light or dark interface style group in the Interface Builder device bar doesn’t take effect when viewing a UIKit storyboard for Mac. (50929581)

  • Projects created with Xcode versions prior to Xcode 11 beta retain their default custom color when opened in Xcode 11 beta. (50828300)

Resolved Issues

  • Dragging out a new iOS Main Menu no longer causes a crash if you drag across an existing menu in the canvas. (51237295)

  • Resolved a performance regression associated with opening storyboards and .xib files. (51282755)

  • The inspector for UIDatePicker now shows only the properties applicable to the selected mode. (26726319)

  • The preview editor’s menu for adding iOS devices now matches the current canvas orientation. (48818470)

  • Preview editor items now preserve the configured locale or pseudo-locale. (48303753)

  • UIDatePicker objects configured as Count Down in Interface Builder now use the specified duration at runtime. (23426425)

  • The Embed In bar button is also visible in documents not using Auto Layout. (46855203)

  • Subclasses of NSControl now have unique icons in the library and document outline. (24231920)


Known Issues

  • Some UI controls from the object library don’t switch to dark mode. (49830961)


New Features

  • LLDB’s Python scripting is now based on Python 3. If you are using Python extensions that aren’t compatible with Python 3, they will break. To help with the transition, you can run in Python 2 mode by setting a default:

    defaults write DefaultPythonVersion 2

    Python 2 support will be removed in the future. (47806994)

  • Swift Decimal values have a data formatter in LLDB, making them display in a readable way. (38983073)

  • LLDB now supports examining Swift types that are compiled with support for library evolution. (48018240)

Resolved Issues

  • Redeclaring self in Swift code works properly with LLDB. (39611934)

  • The Swift REPL and LLDB’s python scripting work properly when the python binary in PATH isn’t the system one. (40961425)

  • Multiple issues that prevented LLDB from accessing variables while debugging XCTest tests are resolved. (41471338)


New Features

  • You can now localize assets in asset catalogs. Localization is enabled in the attribute inspector. (12948139)

  • The settings bundle is now included in Xcode Localization Catalogs. (12495197)

  • The manual page for genstrings has documents its behavior in more detail. (19709369)

  • The genstrings tool is enhanced and merged with the extractLocStrings tool. The previous version is deprecated, has been renamed to ogenstrings, and must now be invoked with xcrun. Any scripts that invoked xcrun extractLocStrings should be changed to use genstrings, but a compatibility symbolic link is currently provided that invokes genstrings. (19709395)

  • The genstrings tool now takes an -encoding argument that allows specification of the file encoding for input files. (48224455)

  • The updated version of genstrings has improved error reporting, and may report errors in scenarios that were previously silently accepted. As an example, genstrings MyApp/* will fail if the MyApp directory contains a subdirectory, because genstrings file arguments are required to be source files. (48304658)

  • The genstrings tool can now take any number of -s arguments to specify additional macros similar to NSLocalizedString or functions from which to extract strings. For example, genstrings -s MyErrorSring -s MyUIString myfile.swift treats both MyErrorString and MyUIString as equivalent to NSLocalizedString. (48734596)

  • The Export for Localization command and genstrings tool now support multiline Swift and Objective-C strings, and have relaxed whitespace requirements when recognizing arguments to NSLocalizedString. (50516442)

  • The performance of the Export for Localization command is substantially improved. (40548416)

Resolved Issues

  • The Export for Localization command and genstrings tool no longer crash on escaped, high Unicode code points such as \U0001F603. (18898240)

  • Importing a localized string that contains embedded newlines now produces strings files with escaped \n sequences. (44649979)

  • XLIFF files produced by Xcode localization export now add xml:space="preserve" to <trans-unit /> elements to ensure that whitespace is preserved. (44928807)


New Features

  • The new Metrics organizer shows battery life and performance analytics for your app to help you drive optimizations.

  • Metrics are reported for your app when distributed on the App Store and after sufficient field use.

  • The available metrics are battery drain, launch time, hang rate, memory, and disk writes.

  • You can filter data by device and usage characteristics. (43028903)


Known Issues

  • SwiftUI live views and inline results in playgrounds aren’t supported in Xcode 11 beta. (42226387)

  • Playgrounds in a workspace can’t import targets from a Swift package. (47668990)

  • The top few lines of a playground might become stuck under the top of the window. Closing and reopening the playground restores scrolling. (47529397)

  • When running on macOS 10.15, playgrounds might encounter a delay in starting execution when in the presence of a slow or unreliable internet connection. (48995467)

    Workaround: Turn off all network connections or move to a more reliable connection to alleviate this delay.

  • Quick looks and inline result previews of views in UIKit may display as blank rectangles. (50787870)

Resolved Issues

  • Playgrounds no longer crash if your code references a view off of the main thread. (46579594)

Project Navigator

New Features

  • Xcode can find assets in your workspace or project using the Find navigator. The Asset catalog Editor also supports find and replace, and you can rename assets using Replace. (14279237)

Reality Composer

Known Issues

  • The RealityKit ARView class isn’t found at runtime when loading a storyboard if its module isn’t specified in Interface Builder. The following error message displays in the Xcode console: “Unknown class ARView in Interface Builder file.” (50840767)

    Workaround: ARView is a Swift view class, and requires both its class name (ARView) and module (RealityKit) to be specified in the Interface Builder inspector.

  • RealityKit’s ARView class is not found at runtime when loading a storyboard if RealityKit isn’t otherwise used within the Xcode project. The following error message displays in the Xcode console: “Unknown class _TtC10RealityKit6ARView in Interface Builder file.” (50900969)

    Workaround: This issue occurs if you import RealityKit and define an @IBOutlet with a type of ARView, but don’t otherwise use RealityKit symbols in your project. To ensure that RealityKit is loaded at runtime with this configuration, manually add RealityKit to your target’s Link Binary with Libraries build phase.

  • Code generated for each scene in a Reality Composer project with multiple scenes that contain notification triggers or notify actions may contain notification triggers and notify actions from other scenes. Calling a notification trigger or a notify action which isn’t part of the loaded scene does nothing. (51008577)

    Workaround: Check your Reality Composer project for which notification triggers and notify actions are available for a given scene prior to calling them.

  • The .reality file generated automatically by Xcode from a Reality Composer project only contains the first scene in the project. (51048599)

    Workaround: Export each scene from Reality Composer as separate .reality files and include them in your app. Alternatively, export all scenes from Reality Composer as a single .reality File and use RealityKit’s load methods to load a particular scene.

Resolved Issues

  • RealityKit is available in iOS simulators. (48603396)


Known Issues

  • Swift packages sometimes don’t appear in the Xcode Server bot configuration Repositories pane. (50058808)

  • Xcode Server is unable to automatically sign apps that use the iCloud, Application Groups, Apple Pay, or Wallet capabilities. (44704694)

    Workaround: Use manual signing to build these projects with Xcode Server.

  • When editing bots for a project that authenticates with SSH, Xcode Server may disable some project-specific settings. (51009722)

    Workaround: Either replace repositories in the Repositories tab when editing the bot or use HTTPS-based authentication with your Xcode Server integrations.

  • Xcode Server can cause a crash when a bot is created from the context menu of any integration. (51082255)

    Workaround: Create bots from the context menu of the server or from the Product menu in Xcode.

  • Xcode Server doesn’t currently support UIKit for Mac. (50602873)

  • Build issues occurring in a source file built by multiple targets may be marked resolved and reintroduced on every integration. (46523551)

Signing and Distribution

New Features

  • Signing and capabilities settings are now combined within a new Signing & Capabilities tab in the Project Editor. The new tab enables using different app capabilities across multiple build configurations. The new capabilities library makes it possible to search for available capabilities. (35254597)

  • Xcode 11 supports the new Apple Development and Apple Distribution certificate types. These certificates support building, running, and distributing apps on any Apple platform. Preexisting iOS and macOS development and distribution certificates continue to work, however, new certificates you create in Xcode 11 use the new types. Previous versions of Xcode don’t support these certificates. (45527608)

Known Issues

  • Xcode 11 throws an error when creating new signing certificates for members of the iOS Developer University Program. (50640287)

    Workaround: Use an older version of Xcode to generate a signing certificate.

  • In-App purchase content bundles may fail to build in Xcode 11 with a code signing error. (50736776)

    Workaround: Add CODE_SIGNING_ALLOWED=NO to the In-App purchase content target’s build settings.

  • Automatic signing may fail with the error “This request is forbidden for security reasons” when creating a development certificate. (50964225)

    Workaround: You may have hit a certificate limit for your account. View your Apple Developer account in Safari and revoke any development certificates that you aren’t using, then try again in Xcode.

  • The archive action does not code sign command-line executable products from Swift packages. (48717735)

    Workaround: Manually sign archived executables using the codesign tool before distributing them.

  • Mac provisioning profiles that you have manually installed using the bot editor’s Signing tab will be installed using the wrong file extension, causing integrations to fail. (47636041)

    Workaround: Sign into your bot user’s account and rename the affected profiles in the ~/Library/MobileDevice/Provisioning Profiles directory.

Resolved Issues

  • Resolved an issue where Xcode incorrectly reported: “No iTunes Connect access for the team” when uploading to the App Store. (39292849)


New Features

  • Metal is available in iOS 13 and tvOS 13 simulators when running on macOS 10.15. Metal code is executed on the host Mac GPU, and is significantly faster than simulated OpenGL code.
The APIs in SceneKit, CoreAnimation, and other system frameworks abstract many differences between GPUs, reducing the need for device-specific code. When running on earlier versions of macOS or in an environment where Metal is not available, simulators continue to use software rendered OpenGL. If your Mac has multiple GPUs, use the File menu in Simulator to select which GPU to use. If the GPU in use becomes unavailable, any simulators using it automatically shut down. (18430676)

  • Xcode no longer creates every available iOS simulator device by default. Instead a set of the most commonly used devices are created. To create other devices — or multiple instances of a device — open the Devices window, select Simulators, click the + button, enter a name, and select the relevant device type and OS version. (49428617)

  • CAMetalLayer is available in iOS 13 and tvOS 13 simulators. (45101325)

  • iOS 13, watchOS 6, and tvOS 13 simulators now have a dyld shared cache. This improves simulator launch times and reduces the number of open file handles used by simulator processes. If you report an issue you believe is related to the shared cache, include a simctl diagnose and the output of launching your program with DYLD_PRINT_LIBRARIES=1. (13632739)

  • simctl now accepts short aliases for runtime names. This means you can create a new iPhone X simulator with a command like simctl create 'iPhone X' iOS13. (41089607)

  • For headless and continuous integration scenarios, you can configure CoreSimulator to skip compositing operations in the virtual frame buffer by setting defaults write FramebufferServerRendererPolicy to none. In this mode simulators can’t be viewed and simctl io is unable to take screenshots or record videos. (48264341)

  • Bundles without a CFBundleVersion are invalid and can’t be properly installed on devices or simulators. CoreSimulator now checks and rejects such bundles earlier in the process with a clearer error message. (49892531)

  • The Simulator dock icon now includes a menu to quickly boot a simulator. (43067512)

  • Simulator’s File menu now includes a GPU selection menu to control which GPU is used by Metal support in simulators and for compositing by Simulator’s virtual frame buffer. If the Use External GPU When Available item is checked, any simulators booted after an external GPU is connected use the external GPU. If the external GPU is disconnected, any simulators using it automatically shut down. Changes to these settings only take effect when a simulator is booted. Simulators already booted when this setting is changed continue using the previously selected GPU until they’re restarted. (46134036)

  • Game controller input is available in iOS simulators. (50082777)

Known Issues

  • Core Image shaders using Metal fail to run iOS 13 simulators with the error “Metal DAG compiler disabled.” (51521248)

  • When running on Apple Watch Series 3, apps built using SwiftUI might behave as if they are running on Apple Watch Series 4. (50678109)

  • Simulator doesn’t deliver game controller events to simulated devices when Simulator isn’t the foreground application when running on macOS 10.15. (51759699)

  • iOS simulators might not color match Metal content to the display’s color space. (50625671)

  • When running on macOS versions before 10.15 some IOSurface instances are leaked by processes running in Simulator. This shows up as high memory usage by SimRenderServer even when no apps are running in simulators. Simulators running on macOS 10.15 aren’t affected. (50880827)

    Workaround: Periodically shutdown any running simulators to release these IOSurface instances and free the memory.

  • iCloud sync isn’t available in iOS simulators. (50924245)

  • Simulator doesn’t display the checkmark for Touch ID > Enrolled when it’s enrolled. (50553667)

  • Automatic synchronization of pasteboards between host and simulated devices does not work. (46686100)

    Workaround: Use Simulator’s manual Get Pasteboard and Send Pasteboard commands.

  • Simulator doesn’t distribute the load if multiple GPUs in a system match the chosen GPU policy. Only the first matching GPU, as returned by MTLCopyAllDevices(), is used. (50608554)

    Workaround: You may see higher performance by locating the simulator window on the display directly connected to the GPU the simulator is using, which avoids copying across GPUs.

  • Video recording of the iOS 13, tvOS 13, and watchOS 6 simulator through xcrun simctl io <UDID> recordVideo returns an error instead of recording video. (50625716)

  • iOS 13 simulators have a simulated display connected even when TVOut is configured as “disconnected". (50829453)

  • Safari’s share to Simulator has no effect. (49331693, 49416352)

  • watchOS simulators don’t honor a breakpoint on a cold boot. (51148192)

    Workaround: Completely boot the simulator before launching the app you’re debugging.

  • The Rotate Device Automatically option in Simulator has no effect in iOS 13 simulators. (51147050)

Resolved Issues

  • Game controllers work properly with iPad simulators. (51034639)

  • Resolved an issue that prevented simulator devices running versions of iOS prior to iOS 13 from rendering the display correctly. (50963987)

  • IOSurface is now functional in iOS 13, watchOS 6, and tvOS 13 simulators. (11051639)

  • Apps in a simulator that plays audio no longer automatically also open the microphone for input. (32406954)

  • The previously deprecated availability field in simctl list’s JSON output is removed. Use the isAvailable Boolean field to determine availability. (45142676)

  • ATSC texture formats are supported by transparently decompressing them on the CPU prior to uploading them to the macOS GPU. (51347811)

Source Control

New Features

  • You can now cherry-pick changes from one branch to another. (18285039)

  • When cloning a new repository, you can now select the branch to check out from the list of available branches. (41122122)

  • Using the new source control file inspector, you can browse the full history of a file for the current branch. The log inspector is available for all file types, including Interface Builder documents. (45109443)

  • You can now stash changes and manage stashes from the source control navigator. Additionally, Xcode offers to automatically stash and restore changes for source control operations like pulling from a repository. (8797804)

  • Source control authors are now available on a per-editor basis. (45108927)

Known Issues

  • Viewing the changes for a revision of a file from the source control log inspector may fail if that file has since been renamed. (49673170)

  • If an author isn’t configured in Preferences > Source Control, pulling with rebase may fail. (48680076)

  • Filtering packages in the Add Package assistant isn’t supported for Bitbucket Cloud or Bitbucket Server hosted accounts. (47290085)

  • Filtering packages in the Add Package assistant isn’t supported for GitLab or GitLab Self-Managed hosted accounts. (47290125)

  • Source control functionality is limited when a Swift package is selected in the Project Navigator, and the content of the Package.swift file is shown. (50696823)

    Workaround: Select the Package.swift file directly before using source control features.

  • When using xcodebuild, resolving packages may fail to verify SSH fingerprints unless that fingerprint is already in the ~/.ssh/known_hosts file. (50686014)

    Workaround: SSH into the host and verify the fingerprint from the command line before using xcodebuild, or manually add the host fingerprint to the ~/.ssh/known_hosts file.

Resolved Issues

  • Resolved issues where hosted account providers like GitHub and BitBucket were unavailable in the add account sheet, and previously added accounts would be disabled. (47645098)

  • Addresses an issue where source control operations in Xcode presented a “Couldn’t communicate with helper application” dialog. (47227781)

  • Fixes a performance issue where Personal, organizational and Starred repositories took a long time to load. (48620126)

  • Addresses an issue where user avatars from GitHub didn’t always load after adding a GitHub account. (48698029)

  • Fixes a bug where some source editor menu options were unavailable in the Code Review Editor. (48774008)

Source Editor

New Features

  • Semantic highlighting, code completion, live issues, symbol search, and jump-to-definition are now supported for the Metal shading language. (45144204)

  • Introduces the ability to view inline code diffs for changes in the Source Editor by clicking on the Source Control Change Bar and choosing Show or Hide Change. (49073551)

  • Added new High Contrast (Dark) theme and High Contrast (Light) theme. Also added new settings for Marks, Type Declarations and Other Declarations. (50036007)

  • Added dedicated syntax coloring for declarations in Swift files, which can be customized in Preferences > Fonts & Colors under Type Declarations and Other Declarations.
Declaration coloring for C-family languages isn’t supported. (10342935)

  • Xcode’s source editor now supports spell checking. (32062963)

  • Xcode 11’s source editor introduces a mini map of the file. The mini map includes legible text for Mark:, highlighted lines with errors and warnings, source control changes, breakpoints, and highlighted Find results. The mini map is enabled by default and can be turned off per editor. (35939517)

  • Added syntax highlighting for markup in documentation comments and playground markup. You can customize the prose font in Preferences > Fonts & Colors under Documentation Markup, and customize delimiter appearance in Preferences > Text Editing > Display. (42941263)

  • Toggle Comments supports multiple cursors. (44319433)

  • When dragging and dropping text, space is opened up between lines to make it easier to see where text will be dropped. When dragging full lines, Xcode only allows drops to occur between other lines. (44735912)

  • The editor allows hierarchical code folding. (47502128)

  • Code folding supports square brackets, and parentheses. (50460404)

  • // MARK: comments and #pragma mark directives now draw a separator line in the editor. The preference for showing mark separators is in Preferences > Text Editing > Display > Show Mark Separators. (7299224)

Known Issues

  • C++ operator overloads aren’t shown in the jump bar. (50841460)

Resolved Issues

  • NSProgressIndicator objects now preserve the current value configured in the inspector when built and run. (43257511)

  • Resolved an issue where Xcode erroneously opened an assistant editor when you ran Fix All Issues using a keyboard shortcut. (37995114)

  • Added dedicated syntax coloring for // MARK: comments and #pragma mark directives, which you can customize in Preferences > Fonts & Colors > Mark. (22114159)

  • You can command-click on Swift operators to use Quick Help and Jump to Definition. (32695862)

  • Resolved an issue that could occur when editing an unclosed block in Objective-C. (48201424)

  • Resolved an issue where code completion sorted deprecated symbols ahead of their nondeprecated counterparts. (38422586)

  • Resolved an issue where code completion rows appeared empty when deleting text. (48621410)

  • Resolved an issue where C++ functions weren’t parsed correctly when using throw or noexcept clauses. (37682611)

  • Accessibility Zoom focus now follows the insertion point in the source editor while typing. (32775118)

  • VoiceOver doesn’t repeat the previous line when moving by line in the source editor. (34334763)

  • VoiceOver has rotors in the source editor for methods, errors, warnings, breakpoints, and marks which makes it easy to search for and move to the line of code corresponding to an error or other rotor item. (34493080)

  • VoiceOver text attributes now include the number of spaces, number of tabs, indent level and line number for a line of code in the source editor. (34607795)

  • VoiceOver no longer speaks extra characters around placeholder tokens when reading in the source editor, and says that they are placeholders. (44941610)

  • Resolved an issue where C++ raw strings didn’t highlight correctly. (10770485)

  • Resolved an issue of issues where C++ class declarations didn’t parse correctly when using qualified names, templates, or multiple inheritance. (11286215)

  • Resolved an issue where local classes nested inside functions or methods weren’t shown in the jump bar. (13337638)

  • Resolved an issue where C++11 trailing return types weren’t properly recognized. (13634062)

  • Resolved an issue where C++ typed enums were not parsed correctly. (13693443)

  • Improved the parsing of declarations that use availability macros and attributes. (14569168)

  • Resolved an issue where C++ numeric literals with single quotes were not recognized. (18121031)

  • Resolved an issue where struct member functions were not parsed correctly. (27946356)

  • Resolved an issue where enum declarations were not displayed in the Jump Bar correctly. (32518576)

  • Improved the recognition of classes and functions in JavaScript. (42537831)

  • Resolved an issue where functions returning enum types were not parsed correctly. (46164630)

  • Resolved an issue where unsigned and long integer literals were not syntax colored correctly. (47138177)

  • Updated JavaScript syntax highlighting to include ECMAScript 6 keywords. (47354463)

  • Fixed an issue where double clicking on a C++ destructor name would also select the tilde (~). (6368356)

Static Analyzer

New Features

  • The static analyzer checks for violations of the MIG calling convention in mach server routines. These violations can lead to use-after-free vulnerabilities. (35380337)

  • The static analyzer checks for violations of IOKit and libkern reference counting rules with respect to out-parameters. (46357478)

  • The static analyzer checks for violations of DriverKit reference counting rules. These violations can lead to leaks and use-after-free issues. (50349513)


New Features

  • The memberwise initializer for structures now provides default values for variables that hold default expressions. (SE-0242, 47130624)

    struct Dog {
        var name = "Generic dog name"
        var age = 0
        // The synthesized memberwise initializer
        init(name: String = "Generic dog name", age: Int = 0)
    let sparky = Dog(name: "Sparky") // Dog(name: "Sparky", age: 0)

  • An @autoclosure parameter can now be declared using a type alias. (SR-2688, 50560849)

    class Foo {
        typealias FooClosure = () -> String
        func fooFunction(closure: @autoclosure FooClosure) {}

  • Methods declared using the @objc attribute inside a class can now return Self. (SR-7601, 50560991)

    class MyClass: NSObject {
        @objc func clone() -> Self { return self }
  • Key path expressions can now include references to tuple elements. (50562288)

  • Single-parameter functions that accept values of type Any are no longer preferred over other functions. (50562333)

  • Conversions between tuple types are now fully implemented. Previously, the following would diagnose an error. (SR-2672, 12340004)

    let values: (Int, Int) = (10, 15)
    let converted: (Int?, Any) = values

  • You can now declare and use type subscripts, just like type properties and type methods. Declare one by applying the static or, in classes, class modifier to the subscript declaration. (SE-0254, 16555559)

    // Declare a type with a static subscript:
    enum ProcessEnvironment {
        static subscript(name: String) -> String? {
            get { getenv(name) }
            set { setenv(name, to: newValue) }
    // Use it with any of these syntaxes:
    ProcessEnvironment["PATH"]! += ":/usr/local/bin"
    ProcessEnvironment["PATH"]! += ":/usr/local/bin"
    someVarOfProcessEnvironmentDotType["PATH"]! += ":/usr/local/bin"

    Type subscripts can also be used with dynamic member lookup to create dynamic type properties.

    // Declare a type with a static subscript:
    enum ProcessEnvironment {
        // …As above…
        static subscript(dynamicMember name: String) -> String? {
            get { self[name] }
            set { self[name] = newValue }
    // Now you can use property syntax with ProcessEnvironment:
    ProcessEnvironment.PATH! += ":/usr/local/bin"
    ProcessEnvironment.self.PATH! += ":/usr/local/bin"
    someVarOfProcessEnvironmentDotType.PATH! += ":/usr/local/bin"

  • Assigning Optional.none to an enumeration that also has a none case, or comparing such an enumeration with Optional.none now produces a warning. Such expressions create an ambiguity because the compiler chooses Optional.none over the none case defined by your own enumeration. (SR-2176, 26126801)

    enum Foo { case none }
    // Assigned Optional.none instead of Foo.none.
    let foo: Foo? = .none
    // Comparing with Optional.none instead of Foo.none.
    let isEqual = foo == .none

    The compiler provides a warning along with a fix-it to replace .none with Optional.none or Foo.none to resolve the ambiguity.

  • Functions can now hide their concrete return type by declaring what protocols it conforms to, instead of specifying the exact return type:

    func makeACollection() -> some Collection {
        return [1, 2, 3]

    Code that calls the function can use the interface of the protocol, but doesn’t have visibility into the underlying type. (SE-0244, 40538331)

  • Enum cases can now be matched against an optional enum without requiring a ‘?’ at the end of the pattern. (SR-7799, 41494702)

    enum Foo { case zero, one }
    let foo: Foo? = .zero
    switch foo {
        case .zero: break
        case .one: break
        case .none: break

  • The existing @dynamicMemberLookup attribute now supports typed key path implementations. (SE-0252, 49069813)

    struct Point {
        var x, y: Int
    struct Box<T> {
        var v: T
        init(_ v: T) {
            self.v = v
        subscript<U>(dynamicMember member: KeyPath<T, U>) -> U {
            get { return v[keyPath: member] }
    var box = Box(Point(x: 0, y: 0))
    _ = box.x

  • You can now use the Self expression to refer to the innermost nominal type inside structure, enumeration and class declarations. For example, the two method declarations inside this structure are equivalent:

    struct Box<Value> {
        func transform1() -> Self { return self }
        func transform2() -> Box<Value> { return self }

    In classes, Self is the dynamic type of the self value, as before. Existing restrictions on Self in declaration types still apply; that is, Self can only appear as the return type of a method. However, Self can now be used inside the body of a method without limitation. (SE-0068, 17892696)

  • Array and ContiguousArray now have the init(unsafeUninitializedCapacity:initializingWith:) initializer, which provides access to the array’s uninitialized storage. (21880692)

  • More thorough checking has been implemented for restrictions around escaping closures capturing in-out parameters or values of noescape type. While most code isn’t affected, there are edge cases where the Swift 5.0 compiler accepted code that violated these restrictions. (SR-8546, SR-9043, 43355341)

    An example of invalid code which was incorrectly accepted by the Swift 5.0 compiler is an @escaping closure that calls a local function that references an in-out parameter from an outer scope:

    struct BadCaptureExample {
        var escapingClosure: () -> ()
        mutating func takesInOut(_ x: inout Int) {
            func localFunction() {
                x += 1
            escapingClosure = { localFunction() }

    The compiler now correctly diagnoses the above code by pointing out that the capture of x by localFunction() is invalid, since localFunction() is referenced from an @escaping closure.

    This also addresses certain cases where the compiler incorrectly diagnosed certain code as invalid, when in fact no violation of restrictions had taken place. For example:

    func takesNoEscape(_ fn: () -> ()) {
        func localFunction() {
        { localFunction() }()

Known Issues

  • APIs deprecated before macOS 10.9 show up as available-but-deprecated rather than unavailable when compiling with the Require Only App-Extension-Safe API build setting, including an old version of read(from:ofType:) that doesn’t support throwing. (51417764)

  • The @frozen attribute for structures and enumerations is unavailable. (36597490)

  • The Swift REPL might not launch from Terminal. (51374106)

  • Declarations with some Protocol return types require the Swift 5.1 runtime in iOS 13, macOS 10.15, watchOS 6, or tvOS 13, but the Swift compiler doesn’t enforce this. Running an app that uses some return types on previous operating system versions might crash at runtime, either because of missing swift_getOpaqueTypeMetadata symbols, or because of a failure to demangle a string that contains the substring “Qo_”. (50731151)

    Workaround: Only deploy binaries that use some return types to iOS 13, macOS 10.15, watchOS 6, and tvOS 13. Avoid them in code that must run on previous operating system versions.

  • If a type has the same name as its containing module, importing that module from a module interface might fail. (48445154)

    Workaround: Rename the type so it no longer conflicts with the module name.

  • If a type uses a some Protocol return type to satisfy an associated type requirement of a protocol, and that associated type is referred to by name inside another generic declaration, the compiler might crash. (50509030)

    protocol HasAssocType {
        associatedtype Assoc
        func assoc() -> Assoc
    struct GenericWithOpaqueAssoc<T>: HasAssocType {
        func assoc() -> some Any { return 0 }
    struct OtherGeneric<X, Y, Z> {
        var x: GenericWithOpaqueAssoc<X>.Assoc
        var y: GenericWithOpaqueAssoc<Y>.Assoc
        var z: GenericWithOpaqueAssoc<Z>.Assoc

    Workaround: Explicitly specify the concrete return type in the declaration that provides the associated type.

Resolved Issues

  • Static libraries are now always force-loaded in their entirety during linking, fixing runtime errors related to demangling failures. (47598583)

  • weak and unowned stored properties no longer inhibit the automatic synthesis of Equatable or Hashable conformance. (SR-9827, 50566123)

  • If symbols in a crash log aren’t properly demangled, run the swift-demangle command and pass in the content of the crash log. (34920390)


Known Issues

  • Instances of PreviewProvider for views with body properties that contain a ForEach view at the top level result in multiple previews. (50711038)

  • Pinching to zoom is unavailable in live previews. (51183125)

    Workaround: Exit live mode or use the zoom controls in the canvas or editor menu.

  • Named colors aren’t editable in the Attributes Inspector. (51287606)

    Workaround: Use the source editor when working with named colors.

  • Selecting then reselecting a named color in the Color inspector might crash Xcode. (51304163)

  • Static previews for iOS, tvOS, and watchOS don’t support SceneKit, MapKit, and Metal views, and experience a delay when rendering updates. (50965310)

  • Drag and drop operations that result in insertions of containers around an existing view and a new sibling in the container don’t work if the existing view is at the top level of a conditional statement in a view builder. For example, you can’t drop an HStack or VStack around the Text. (50300406):

    var body: some View {
        VStack {
            if true {
                Text("Hello World")

    Workaround: Embed the existing view into a container — either in the canvas or the source editor — then drop the new view into that container.

  • Static watchOS previews show black text on a black background. (51676439)

    Workaround: Apply the colorScheme(.dark) modifier to the previews.

  • Previews in packages always perform a full build of the active scheme. (51030302)

  • Dragging a Text modifier onto text in the canvas that already has a View modifier such as frame(width:height:alignment:) results in a compilation error. (50712235)

    Workaround: Reorder the modifiers so that modifiers specific to Text appear before any View modifiers.

  • Using withAnimation(_:_:) to change state in a root view isn’t reflected in live previews. (51164838)

  • HStack and VStack inspectors don’t support custom layout guides. (49710501)

    Workaround: Use the source editor for custom layout guides.

  • The attribute inspector doesn’t allow specifying flexible frames. (51310989)

  • Entering live preview mode in the canvas might take several seconds the first time. (46505269)

  • PreviewProvider instances defined in projects that don’t have -DDEBUG set for OTHER_SWIFT_FLAGS that are also wrapped in #if DEBUG conditionals don’t display in the canvas. (51138834)

    Workaround: Remove the conditional compilation block from around the PreviewProvider declaration.

  • Animations may escape out of their context in live previews. This may cause live previews to not match on-device previews. (50708417)

  • Opening the same file in a new window then closing that window causes previews in the first window to display an error. (47619828)

    Workaround: Choose Try Again in the first window when the error appears.

  • Previews may fail or update incorrectly when switching between files. (50841287)

    Workaround: Add a newline to the end of the active file, then click Resume in the banner that appears.

  • The attributes inspector stays visible after the canvas closes, gets stuck on the last selected item, and doesn’t function. (50958316)

    Workaround: Reopen the canvas or switch to a different file.

  • watchOS previews might fail if you select a physical phone that’s paired with a watch as the run destination from the Scheme pop-up menu. (50861269)

    Workaround: Select a watchOS simulator while working with previews.

  • Previews don’t work for macOS apps with App Sandbox enabled. (51088926)

  • Previews don’t appear in the canvas for private and fileprivate structures that conform to PreviewProvider. (47011316)

    Workaround: Remove the private or fileprivate access control from your conforming type.

  • Previews might take several seconds to update when switching devices in the run destination selector the first time. (47562171)

  • Previews might temporarily show the incorrect device chrome when switching devices using the run destination from the Scheme pop-up menu. (49496647)

  • The canvas doesn’t support focus. (50275735)

  • Undo is unavailable in the canvas. (49651153)

    Workaround: Bring the source editor into focus and perform the undo there.

  • The insertion indicator only shows on the topmost item for repeated content such as content in a List or ForEach view. (50244112)

SwiftUI Tutorials

Known Issues

  • After following Section 7, Step 7 in the Building Lists and Navigation tutorial in Xcode, you might encounter an error in your project’s SceneDelegate.swift file. (51334559)

    Workaround: Update line 14 of SceneDelegate.swift to use LandmarkList instead of LandmarkDetail:

    window.rootViewController = UIHostingController(rootView: LandmarkList())

  • After following Section 5, Step 3 in the Handling User Input tutorial in Xcode, you might encounter an error in the preview provider. (51341785)

    Workaround: Undo the change to the LandmarkDetail initializer, so that you only add the environmentObject(_:) modifier:

    struct LandmarkDetail_Preview: PreviewProvider {
        static var previews: some View {
            LandmarkDetail(landmark: landmarkData[0])

Swift Packages

Known Issues

  • Previews aren’t supported for standalone packages. (51072409)

  • Swift packages don’t support adding resource files — such as images, storyboards, or audio — in a target. (SR-2866, 33389529)

  • Searching for package repositories in the Add Package Dependency sheet might not complete when there are no search results. (51223367)

    Workaround: Cancel the search, enter the repository URL in the text field, then select Next.

  • Code completion doesn’t work for Swift package targets if the name of the target declared in the Package.swift manifest file differs in casing with the directory name for that target. (49648458)

    Workaround: Use path property to provide the exact casing of target’s name as on disk or update target name in the manifest to match the directory name on disk.

  • Adding a new file in a C-family target of a Swift package creates the file with the .swift extension. (31395814)

    Workaround: Rename the new file with the desired extension.

  • Swift packages don’t support adding resource files — for example, images, storyboards, or audio — in a target. (SR-2866)

  • Swift packages don’t support processing localized strings files. (48190792)

  • Moving a local package in a project will convert it into a folder reference. (50320585)

  • A package product that is linked into both app and its test target results in duplicated symbols. (50348625)

    Workaround: Link a package product only in the app or test target.

  • Swift packages that use unsafeFlags build settings aren’t supported. (50354068)

  • The scheme that’s autogenerated for a Swift package isn’t automatically updated when the package adds or removes targets. (50586754)

    Workaround: Delete the scheme from the swiftpm/xcode/xcshareddata/xcschemes directory inside the package directory, then reopen the package to automatically generate a new scheme.

  • Targets of a Swift package build with debug-conditional settings if the build configuration selected in the scheme is not named Debug or Release. (50696202)

  • Removing a local package reference from a workspace removes its package products from all Xcode targets in the workspace, even when other references to that local package remain in the workspace. (50706448)

    Workaround: Add package product references back to the relevant targets.

  • Previewing code in Swift packages which are not referenced by the active scheme and not being linked into an app target is not supported and shows an incorrect error message. (50909384)

  • Test targets of newly-created Swift packages fail to build for watchOS because XCTest is unavailable on watchOS. (51054894)

    Workaround: Surround any code in watchOS test targets which references the XCTest framework or its APIs with conditional compilation statements. For example:

    #if !os(watchOS)
    // XCTest code

  • Xcode crashes if a local package overrides a remote package in a project and the local package has an unsatisfiable package dependency. (51183216)

    Workaround: Open the local package separately in Xcode and ensure that its package dependencies are resolvable.


New Features

  • Support for writing XCTest-based tests for apps that adopt SwiftUI. (35224680)

  • Test Plans are a new way to manage which tests run, and how those tests run. Schemes can reference multiple test plans, and define a default test plan for automation. A new Test Plan editor supports defining test configurations, which can inherit shared settings from the plan itself. Running tests in Xcode now runs tests across all test configurations. The Source Editor test diamonds are updated to support running a test in a single configuration, and the Test Navigator is updated to allow choosing the active test plan. Test reports are updated to support displaying results generated by a test plan. (16138582)

  • XCTest includes augmented performance testing capabilities with the new measure(metrics:options:block:) method and related methods. The metrics argument requires a list of objects conforming to the XCTMetric protocol. You can either implement your own custom metrics or use XCTClockMetric, XCTOSSignpostMetric, XCTCPUMetric, XCTMemoryMetric, or XCTStorageMetric. (49430032)
The following shows an example performance test that measures the CPU and Memory impact of sorting a list:

    func testExample() {
        // Measures the CPU and memory impact of sorting the input list.
        measure(metrics: [XCTCPUMetric(), XCTMemoryMetric()]) {
            sortedList = qsort(list: self.fiftyNumbersFrom0to100)

  • Added an assertion function, XCTUnwrap, for use in Swift tests. XCTUnwrap asserts that an Optional variable’s value is not nil, returning its value if the assertion succeeds. This removes the need to combine XCTAssertNotNil(_:_:file:line:) with either unwrapping the value or dealing with conditional chaining for the rest of the test. For example:

    func testFirstNameNotEmpty() throws {
        let forenames: [String] = customer.forenames
        let firstName =  try XCTUnwrap(forenames.first)

    XCTUnwrap is a throwing assertion, and is best used in a throwing test method as in the above example. (30667432)

  • xccov now supports being passed result bundles directly, in addition to raw report and archive files. For example, to view the coverage report within a result bundle, invoke xccov as follows: xccov view --report /path/to/result_bundle.xcresult. (50500789)

  • The format of result bundles changed in Xcode 11. A result bundle is an asset produced by Xcode 11 with the xcresult file extension that contains information about the build, tests, code coverage, and more. Any xcresult files produced with Xcode 10 or earlier cannot be read by Xcode 11. A result bundle can be produced by passing -resultBundlePath ./Example.xcresult to an xcodebuild invocation and the Example.xcresult can then be opened in Xcode. Xcode also creates result bundles in Derived Data. The current result bundle version number is 3, which can be specified by passing the xcodebuild flag -resultBundleVersion 3. Version 3 is the default in Xcode 11, but it is still recommended for automation to explicitly pass the flag, so that any potential future versions that become the default do not cause issues to existing tools. Result bundles can be inspected using xcresulttool. A JSON representation of the root object of the result bundle can be exported using xcrun xcresulttool get --format json --path ./Example.xcresult and any nested object, identified by its reference found in the JSON output, can be exported by adding the flag --id REF. xcresulttool also provides the description of its format using xcrun xcresulttool formatDescription. (41633595)

  • If a test runs on multiple destinations and fails on some but not others, the test report displays a summary describing the destinations on which the test failed, e.g. “Failed on iPad destinations running iOS 12.0”. (49164968)

  • When running a test or test class via a source editor test diamond, option-clicking the diamond presents a popover that allows the test to be run under a specific configuration in the active test plan (if the test plan has multiple configurations). (46348663)

  • When viewing a test report for tests that ran on multiple destinations (such as an Xcode Server integration, or a result bundle generated by an xcodebuild invocation with multiple destination specifiers), it’s now possible to filter the displayed results by destination. Clicking on the devices button in the scope bar will present a list of the destinations on which the tests ran, including the ability to hide or show only the destinations of interest. In addition, it’s now possible to filter to only those tests that failed on one destination but succeeded on another, via the “Mixed” button in the scope bar. (48981032)

  • Result bundles produced by xcodebuild can now be shared, double-clicked, and opened in Xcode directly. (38620469)

  • Introduces support for writing XCTest-based tests for applications that adopt UIKit For Mac. (41530313)

  • Code Coverage is now enabled by default for newly created test plans. (48749597)

  • In UI testing on macOS, mouse moves, including calls to the hover API as well as calls to click, scroll, and other APIs will move the cursor progressively across the screen, just as a user would in real interactions, rather than instantly moving the cursor to the final location. This may cause problems for tests involving UI that is heavily dependent on mouseover behavior. (49430331)

  • The .xctestrun file format is modified for Test Plans to include information about how to perform each test configuration in the plan. When running xcodebuild build-for-testing for a scheme that uses test plans, the generated .xctestrun files use FormatVersion 2 and have a revised property list structure. .xctestrun files generated for schemes which don’t use test plans continue to use FormatVersion 1, and xcodebuild test-without-building accepts either version. (46346053)

  • The Code Coverage setting in the test plan editor doesn’t support selecting individual targets to gather code coverage for. If the test plan was created by converting a scheme to use test plans, and that scheme had individual code coverage targets selected at the time of conversion, those targets are preserved in the resulting test plan but aren’t editable within the plan. (50502861)

  • xcodebuild is enhanced with new options supporting Test Plans. Use the new -showTestPlans option to list all test plans associated with a scheme. Use the new -testPlan <name> option to specify which test plans associated with a scheme to use for testing or building tests. If -testPlan <name> is not specified, xcodebuild test will use the scheme’s default test plan. (46346197)

  • Xcode 11 introduces the option to automatically include screenshots from XCTest in Xcode Localization Catalogs. Enable Localization Screenshots in your test plan or in the scheme editor, then check “include screenshots” when exporting for localization. (28656175)

Known Issues

  • The Execute in Parallel checkbox in the test action of a scheme is disabled for test targets of a Swift package. (47564543)

  • The test plan editor allows enabling certain combinations of sanitizers and memory diagnostics which are incompatible and should not be simultaneously enabled. For example, Address Sanitizer and Guard Malloc, or Address Sanitizer and Thread Sanitizer. (49739613)

    Workaround: Don’t configure a test plan with a combination of sanitizers and memory diagnostic settings which are incompatible. If an incompatible setting is inherited in a test configuration by the test plan’s Shared Settings, manually override the setting to disable it for the affected test configuration.

  • Editing a test plan which references test targets in a different project than the project which contains the active scheme will cause those test targets to be labeled “Missing”. (50148373)

    Workaround: Switch the active scheme to a scheme contained by the same project where that plan’s test targets are defined.

  • In a workspace that contains Swift packages, attempting to run tests while the packages are being resolved can cause Xcode to be unable to run tests until the workspace is reopened. (48719922)

    Workaround: Wait until all packages are downloaded and resolved before running tests.

  • The new XCTUnwrap API is not available when building Swift package tests using the Swift Package Manager. (51115369)

  • In UI tests for UIKit apps on macOS, attempts to interact with elements inside of a table view cell may fail with an error about hit testing. (50745246)

    Workaround: Perform the interaction on an XCUICoordinate instance that represents the midpoint of the element. For example:

    app.cells.staticTexts["My Cell Content"]
            withNormalizedOffset: CGVector(dx: 0.5, dy: 0.5)

  • Running tests with code coverage enabled fails to produce a coverage report for iOS apps in the simulator or on a Mac. (51091751)

Resolved Issues

  • Resolved a crash that could occur while checking for device availability when starting a testing operation. (51245770)

  • Resolved an issue that prevented code coverage reports from being generated for iOS apps that are run in Simulator or on a Mac. (51241460)

  • The exists property on XCUIElement now produces test failures in situations where XCTest is unable to inspect the application’s UI — for example, due to the app’s main thread being unresponsive — instead of returning false in those situations. (37359653)

  • The unit test discovery mechanism is more efficient for large projects. The test navigator gets populated faster after reopening a project. (32567980)

UIKit for Mac

Known Issues

  • On-Demand Resources (ODR) aren’t supported on macOS, so when you build an iOS target that uses ODR for the Mac, you’ll need to make some changes. Xcode automatically disables ODR so that those resources are built into the bundle of the target building them, rather than in separate asset bundles. Update your code to load those resources from the app bundle rather than from asset bundles. (50358184)

  • The color asset variant for UIKit for Mac isn’t passed at runtime. (51113192)

  • The NSDataAsset asset variation for UIKit for Mac returns nil at runtime. (50022757)