Hello, I have a raw device number, as an input, for external usb/thunderbolt device (i.e. for /dev/disk9 - it is 9). And I want to format it to APFS or read/confirm APFS FS type if it is already formatted. But I can see that APFS container/volume have another disk number (i.e /dev/disk10) in compare with for my raw disk. Is there a guaranteed way to match raw disk number to underlying APFS container/volume disk number? May be some API? Or just add +1 to raw disk number for getting APFS container/volume disk device number?

I have successfully booted the Linux Kernel with VirtIOFS as the rootfs, but file permission issues render it completely unusable. A file on the macOS host belongs to uid 0, gid 0, but on the Linux guest, this file belongs to uid 1000, gid 10. Why does this happen? How are file permissions directly mapped between the host and the guest? If there is no mapping mechanism in place, why does this discrepancy occur? This leads to errors in Linux, such as: sudo: /etc/sudo.conf is owned by uid 1000, should be 0 sudo: /usr/bin/sudo must be owned by uid 0 and have the setuid bit set bootLoader.commandLine = "console=hvc0 rootfstype=virtiofs root=myfs rw" let directorySharingDevice = VZVirtioFileSystemDeviceConfiguration(tag: "myfs") directorySharingDevice.share = VZSingleDirectoryShare(directory: VZSharedDirectory(url: rootURL!, readOnly: false)) The VMM is running as root.

I'll try to ask a question that makes sense this time :) . I'm using the following method on NSFileManager: (BOOL) getRelationship:(NSURLRelationship *) outRelationship ofDirectoryAtURL:(NSURL *) directoryURL toItemAtURL:(NSURL *) otherURL error:(NSError * *) error; Sets 'outRelationship' to NSURLRelationshipContains if the directory at 'directoryURL' directly or indirectly contains the item at 'otherURL', meaning 'directoryURL' is found while enumerating parent URLs starting from 'otherURL'. Sets 'outRelationship' to NSURLRelationshipSame if 'directoryURL' and 'otherURL' locate the same item, meaning they have the same NSURLFileResourceIdentifierKey value. If 'directoryURL' is not a directory, or does not contain 'otherURL' and they do not locate the same file, then sets 'outRelationship' to NSURLRelationshipOther. If an error occurs, returns NO and sets 'error'. So this method falsely returns NSURLRelationshipSame for different directories. One is empty, one is not. Really weird behavior. Two file path urls pointing to two different file paths have the same NSURLFileResourceIdentifierKey? Could it be related to https://developer.apple.com/forums/thread/813641 ? One url in the check lived at the same file path as the other url at one time (but no longer does). No symlinks or anything going on. Just plain directory urls. And YES calling -removeCachedResourceValueForKey: with NSURLFileResourceIdentifierKey causes proper result of NSURLRelationshipOther to be returned. And I'm doing the check on a background queue.

Hello! Some colleagues and work on Jujutsu, a version control system compatible with git, and I think we've uncovered a potential lock contention bug in either APFS or the Darwin kernel. There are four contributing factors to us thinking this is related to APFS or the Kernel: jj's testsuite uses nextest, a test runner for Rust that spawns each individual test as a separate process. The testsuite slowed down by a factor of ~5x on macOS after jj started using fsync. The slowdown increases as additional cores are allocated. A similar slowdown did not occur on ext4. Similar performance issues were reported in the past by a former Mercurial maintainer: https://gregoryszorc.com/blog/2018/10/29/global-kernel-locks-in-apfs/. My friend and colleague André has measured the test suite on an M3 Ultra with both a ramdisk and a traditional SSD and produced this graph: (The most thorough writeup is the discussion on this pull request.) I know I should file a feedback/bug report, but before I do, I'm struggling with profiling and finding kernel/APFS frames in my profiles so that I can properly attribute the cause of this apparent lock contention. Naively, I ran xctrace record --template 'Time Profiler' --output output.trace --launch /Users/dbarsky/.cargo/bin/cargo-nextest nextest run, and while that detected all processes spawned by nextest, it didn't record all processes as part of the same inspectable profile and didn't really show any frames from the kernel/APFS—I had to select individual processes. So I don't waste people's time and so that I can point a frame/smoking gun in the right system, how can I can use instruments to profile where the kernel and/or APFS are spending its time? Do I need to disable SIP?

I’m debugging a custom BLE HID device on iPhone. It is a composite HID mouse + keyboard dongle. Setup: Hardware: Seeed XIAO nRF52840 Firmware: Adafruit Bluefruit Arduino / BLEHidAdafruit BLE HID report map: stock Adafruit composite HID with keyboard, consumer, and mouse reports GAP/advertising appearance: HID_MOUSE iOS adopts the device as an AssistiveTouch pointer Mouse movement and clicks work correctly Keyboard symptom: Lowercase/unshifted characters type correctly. Shifted characters lose the Shift modifier during text input: - A -> a - T -> t - DoorDash -> doordash - ! -> 1 - @ -> 2 - # -> 3 - { -> [ - } -> ] Confirmed: The iOS app sends the exact intended string to the dongle. Firmware receives the exact string. Firmware computes and sends the expected HID modifier/keycode: A sends modifier 0x02 + HID_KEY_A ! sends modifier 0x02 + HID_KEY_1 A lone isolated "A" still lands as "a", so this does not appear to be a timing or repeated-key issue. Cmd+Space works from the same HID keyboard report path and opens Spotlight. Full Keyboard Access is off. Turning AssistiveTouch off does not fix it. The iPhone never shows "Hardware Keyboard" settings for this device, even when searching Settings. Question: Is there a documented distinction on iOS between accepting BLE HID keyboard reports for global shortcuts, such as Cmd+Space, and admitting the same device as a full Hardware Keyboard for text composition? In particular: Does the absence of Hardware Keyboard settings mean iOS has not classified the device as a real external keyboard? Can a composite BLE HID device advertised as HID_MOUSE be accepted for pointer input but have Shift ignored for text input? Does iOS require a different GAP appearance, HID report-map structure, report ordering, or separate keyboard identity for Shift/modifier text composition to work? Is there a recommended way to build a BLE HID device that preserves AssistiveTouch pointer behavior while also being treated as a full external keyboard?

Hi, I’m looking for clarification on Apple Pay merchant domain verification behavior. Our production domain’s verification expiry was extended without any action from our team. Previous expiry: May 21, 2026 Current expiry: October 6, 2026 The Verify button is greyed out, and we can’t download a new .txt file. We did not re‑verify the domain during this time. A few weeks prior, we did renew our Apple Pay Merchant Identity certificate for Apple Pay on the web. Could someone clarify: Does updating the Merchant Identity certificate trigger automatic domain revalidation or expiry extension? If so, why was the extension only 4 months? Does Apple automatically revalidate or extend merchant domain verification? Is this expected behavior, or should domains always be manually re‑verified?

Hello, We are currently integrating the new Declared Age Range framework to comply with the age assurance requirements (such as the Texas regulatory rollout). We are specifically trying to test the AgeRangeService.RegulatoryFeature.significantAppChangeRequiresParentalConsent flow for minors. The Problem When testing in the Sandbox environment, the consent flow returns a mocked response immediately. While this validates our basic code logic, it does not allow us to test or see the actual end-to-end user experience/UI of the parental consent flow. When we attempt to test this outside of the Sandbox environment on a production build/device to see the true system UI, the AskCenter.ask(PermissionQuestion, in: ...) request fails immediately with the following error: Error: “The user is in a region that does not support this type of ask." UserInfo: {NSLocalizedDescription=The user is in a region that does not support this type of ask., NSLocalizedRecoverySuggestion=Please ensure the user is in an eligible region., NSLocalizedFailureReason=The user must be in a supported region to use this feature.} What We Have Tried Verified that our App Store Connect Sandbox account and test devices are configured correctly according to the "Testing Age Assurance in Sandbox" documentation. Attempted to change the region/location settings on our physical test devices to Texas/US to trigger the real flow, but the production environment still blocks it with the region error. Reviewed existing forum threads (such as 809889 and 809483) where other developers are facing the exact same roadblock without a clear solution. Our Questions Is there any supported way to trigger the full, unmocked system consent UI end-to-end during development/local testing? If changing the device's region settings isn't enough to bypass the production region check for AskCenter, how does Apple determine region eligibility for this specific API during local evaluation? Any insights, workarounds, or configuration steps to properly preview this UI before app submission would be greatly appreciated. Thank you!

I have several Swift Data types with a property of type enum. Whenever I've tried to write a predicate returning data objects only of a certain enum case, the compiler throws an error from the macro at build time. (which I don't have handy, sorry...). Is this supported? And if so, how would you write the predicate? @Model public final class AlbumList { // ... public var listType: AlbumListType // ... } public enum AlbumListType: String, CaseIterable, Codable { case listener case dj }

I have a SwiftData app that runs on iOS, iPadOS, and MacCatalyst and which uses CloudKit for inter-device sync. Unfortunately, I also have two AppleIDs (which I 'll refer to as OLDID and NEWID). Although all three devices (phone, pad and desktop) are currently set up with NEWID as the active AppleID, during development and testing, my desktop Mac used OLDID. Apparently, the system remembers the AppleID to use with each CloudKit app (based on the AppleID active at time of first use), because the desktop app and the mobile apps apparently sync to different AppleID accounts. I can delete the local database on the desktop and delete the local app on the mobile devices and in each case, reloading/rerunning the app causes the respective databases to be restored from the cloud. The two mobile devices sync with each other, but not with the desktop; the desktop doesn't sync with either device. And the two databases have decidedly different contents. My goal is to consolidate everything so that there is one database, shared and synced between desktop, pad, phone and cloud. I presume that there is a setting somewhere (but clearly NOT in the app's sandboxed container) that specifies what iCloud account to use for that (and each) app. Note: I have other apps which sync between all my devices, so the setting must be on a per-app basis. I also presume that if I changed it's value on my desktop (so that all three devices used the same AppleID for cloud services for my app), that the content of the local database on my desktop would be synced automatically to the NEWID cloud account and then (also automatically) synchronized with my mobile devices. I.e., I speculate that I can solve all my problems by changing that setting on my desktop Mac. So I have two questions: Is all this correct? How do I make this setting change. (I.e., where is it and how do I change it) Does anyone have any experience and can help with this issue? Thanks

It would be good if SensorKit was more available for non research related apps. For example I want to create an app that tracks light sensor values to create a mapping of bikelanes with poor lighting. This doesn’t fall under a research app, but seems like a reasonable use of this data. creating a way to opt the user into this (via clear warnings that the data Is being collected, and maybe a 24 or 1 hour time limit) might be a way to make this sensor data available. also clear warnings on the app store privacy page, or maybe even rules about running in the background or at app startup and an icon in the toolbar (similar to the mic) could make this more safe for users.

We're developing a custom Thunderbolt device and want to expose it to macOS as an ethernet interface, while owning the full network stack implementation up to and including IP, TCP and UDP — bypassing the macOS network stack for those layers. Is IOEthernetController the right DriverKit approach for this, and does it allow intercepting traffic before it reaches the macOS IP stack?

Summary: Starting from iPadOS 26.4, the maximum memory available to a single app has been reduced from approximately 6GB to 3GB on an 8GB iPad. This change persists in iPadOS 26.5 and has not been addressed. This breaks core functionality of memory-intensive applications such as 3D scanning apps that require large amounts of RAM to process models. Device: iPad with 8GB RAM Affected versions: iPadOS 26.4, iPadOS 26.5 Working version: iPadOS 26.0 / 26.1 / 26.2 / 26.3 Measured Data: iPadOS 26.0–26.3: App available memory ≈ 6GB (75% of total RAM) iPadOS 26.4–26.5: App available memory ≈ 3GB (37.5% of total RAM) Measurement method: Apple system API Impact: This is a regression, not expected behavior. The available memory per app has been cut by 50% without any official documentation or release notes mentioning this change. As a result, our 3D scanning application crashes immediately when attempting to process 3D models on iPadOS 26.4 and later. The app requires substantial RAM to load and process 3D model data. With only 3GB available, memory allocation fails during model processing, causing the app to crash (EXC_RESOURCE / OOM kill). This core functionality was working correctly on iPadOS 26.3 and earlier with the same device and same app binary. This regression makes our app's primary feature completely unusable for all users on iPadOS 26.4+. Steps to Reproduce: On an 8GB iPad, install iPadOS 26.0 Measure available app memory using Apple system API Upgrade to iPadOS 26.4 or 26.5 Measure available app memory again Observe: available memory drops from ~6GB to ~3GB Expected Result: Available memory per app should remain consistent across minor OS updates, or any changes should be documented. Actual Result: Available memory per app dropped by 50% starting in iPadOS 26.4, with no documentation of this change. Additional Notes: Disabling Apple Intelligence does not resolve the issue This issue was not fixed in iPadOS 26.5 Other developers have reported increased crash rates starting in iPadOS 26.4 (Apple Developer Forums)

On a MacBook Pro, 16GB of RAM, 500 GB SSD, OS Sequoia 15.7.1, M3 chip, I am running some python3 code in a conda environment that requires lots of RAM and sure enough, once physical memory is almost exhausted, swapfiles of about 1GB each start being created, which I can see in /System/Volumes/VM. This folder has about 470 GB of available space at the start of the process (I can see this through get info) however, once about 40 or so swapfiles are created, for a total of about 40GB of virtual memory occupied (and thus still plenty of available space in VM), zsh kills the python process responsible for the RAM usage (notably, it does not kill another python process using only about 100 MB of RAM). The message received is "zsh: killed" in the tmux pane where the logging of the process is printed. All the documentation I was able to consult says that macOS is designed to use up to all available storage on the startup disk (which is the one I am using since I have only one disk and the available space aforementioned reflects this) for swapping, when physical RAM is not enough. Then why is the process killed long before the swapping area is exhausted? In contrast, the same process on a Linux machine (basic python venv here) just keeps swapping, and never gets killed until swap area is exhausted. One last note, I do not have administrator rights on this device, so I could not run dmesg to retrieve more precise information, I can only check with df -h how the swap area increases little by little. My employer's IT team confirmed that they do not mess with memory usage on managed profiles, so macOS is just doing its thing. Thanks for any insight you can share on this issue, is it a known bug (perhaps with conda/python environments) or is it expected behaviour? Is there a way to keep the process from being killed?

I'm trying to get Apple's new Bluetooth Channel Sounding distance measurement working between an iPhone running iOS 27 Beta and a Nordic nRF54L15-based board. The CS procedures appear to execute successfully over the air (Mode 0 + Mode 2 with Inline PCT), but the iOS sample app consistently returns 0 distance readings and occasionally throws Channel Sounding configuration failed. What specific validation does iOS 27 apply to CS results before surfacing them ? Are there known compatibility requirements for Nordic nRF54L15 with iOS Channel Sounding? (Nordic has indicated they're working on official support but have no timeline) Is there a publicly available hardware and/or firmware platform already available we can use to test? PacketLogger log nRF54L15 log

Hello, I am developing a cross-platform mobile app that communicates with an external accessory over a serial (UART) link. HARDWARE : The accessory is an optical reading probe that connects to the phone via USB. Inside the cable there is a standard FTDI USB-to-serial chip (similar to common FTDI/CP210x USB-serial adapters). WHAT WORKS On Android, our app: Detects the USB device Opens the serial port Reads and writes raw bytes successfully This wired FTDI path is fully implemented and working. WHAT DOES NOT WORK On iPhone, using the same wired FTDI USB accessory: We connect via Lightning or USB-C adapter The app never sees the FTDI device We cannot find a public iOS API to open a generic USB-serial port MY QUESTION : Is there any supported way for a third-party iOS app to communicate with a generic FTDI USB-serial device over a wired USB connection? Specifically, am I missing: A public Apple framework for USB serial? An Info.plist key or entitlement? A system driver on iOS similar to macOS AppleUSBFTDI (TN2315)? Or is wired USB-serial on iPhone only possible with MFi-certified accessories (External Accessory framework) or another transport such as Bluetooth LE? WHAT I HAVE ALREADY CHECKED External Accessory: seems to require MFi hardware and a registered protocol string. Our FTDI probe is not MFi. TN2315 (AppleUSBFTDI): appears to be macOS only, not iOS. Physical USB connection: cable fits, but no serial API is exposed to the app. ENVIRONMENT Platform: iOS (iPhone) Language: C# / .NET-iOS Need: transparent byte-level serial read/write SUMMARY: Android USB-serial works with our FTDI wired accessory. iOS does not. Am I missing something on iOS, or is generic FTDI USB-serial simply not supported for third-party iPhone apps? Thank you for any guidance.

I have the following code - you can see where I had to comment out the code on the simulator. Is this expected? The code works perfectly fine on a physical iPad device. Is it documented somewhere that NSFileVersion doesn't work with non-local versions in the simulator? func loadPreviewDirectly( from version: NSFileVersion, completion: @escaping (CIImage?) -> Void ) { let versionURL = version.url let access = versionURL.startAccessingSecurityScopedResource() defer { if access { versionURL.stopAccessingSecurityScopedResource() } } print("Loading version: \(version.persistentIdentifier) | Local: \(version.hasLocalContents)") // 1. SIMULATOR CATCH: If running in simulator and the file is missing, it will never download. #if targetEnvironment(simulator) if !version.hasLocalContents { print("⚠️ iOS Simulator cannot materialize remote NSFileVersions. Fallback triggered.") // You cannot test remote versions here. For testing on the simulator, // test with a version where version.hasLocalContents == true (created locally in this session). DispatchQueue.main.async { completion(nil) } return } #endif let coordinator = NSFileCoordinator() var coordinationError: NSError? // 2. Wrap everything in a sequential reading coordination coordinator.coordinate(readingItemAt: versionURL, options: [], error: &coordinationError) { readURL in let image = CIImage(contentsOf: readURL) DispatchQueue.main.async { completion(image) } } if let error = coordinationError { DispatchQueue.main.async { self.errorMessage = error.localizedDescription completion(nil) } } }

LiveActivity using colorScheme to adapt to dark mode in iOS 26 system does not work The system keeps returning. mark, unable to switch

I am porting a project from the now deprecated dns_util api to use the DNS Service Discovery api. With dns_util I am able to specify a DNS name server to use for resolving queries. This is useful for testing new servers or propogation when changes have been made to DNS records. Is it possible to specify the nameserver to use with DNS Service Discovery?

This post contains sensitive language. Please revise it in order to continue.Hello, We are working on digital key style application using custom communication with HCE (Host Card Emulation). We have a working solution but there is one issue - if our application is not selected as default NFC application our users may see Wallet popup when there's no active presentment intent in our application. I didn't find in documentation any information how to stop Wallet from activating. I found there's requestAutomaticPassPresentationSuppression method in PassKit, it requires special permission, however I am not sure if it can be used in this situation, as there's no information how it will impact HCE communication in our application. I'll be greatful for any advice. Regards, Valdemar

Hello, We are currently developing an application that uses the Host-based Card Emulation (HCE) entitlement to enable corporate access functionality. With this entitlement, we have successfully established HCE communication and can interact with our access control systems to unlock doors. Our question is related to improving the user experience: We would like this access functionality to work without requiring the app to be in the foreground, as this adds friction for users during entry. Specifically, we would like to know: Is it possible for our app to coexist with Apple Wallet as the default contactless app, so that: Our app handles NFC interactions for corporate access (e.g., opening doors). Apple Wallet remains the default for payments. If that coexistence is not possible, and our app is set as the default contactless app, Will the system still need to launch our app into the foreground to complete a transaction (e.g., to emulate the NFC card)? Or is there a way to trigger HCE responses in the background (e.g., using a background process or service extension)? Any guidance on how to configure the app for optimal background access behavior, while maintaining compatibility with Wallet, would be greatly appreciated. Thank you in advance.