General: DevForums subtopic: App & System Services > Core OS Core OS is a catch-all subtopic for low-level APIs that don’t fall into one of these more specific areas: Processes & Concurrency Resources Files and Storage Resources Networking Resources Network Extension Resources Security Resources Virtualization Resources Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com"

Since updating the OS to 26.4, the app has been crashing more often after I launch it. The devices on which this issue has been confirmed are as follows: ・iPhone SE (2nd generation) ・9th-generation iPad ・8th-generation iPad ・5th-generation iPad mini We have confirmed that the application functions properly on all devices prior to the OS update.

I’m running into a hardware reality. MEMS sensor thermal drift. If a user zeroes out the tilt indoors at 20°C and then takes the phone outside in the cold, the accelerometer baseline shifts just enough as the device cools to throw off the readings. I want to apply a simple thermal compensation curve to the CoreMotion data to keep the "zero" perfectly level regardless of the weather. However, ProcessInfo.thermalState only gives broad buckets (nominal, fair, etc.) which doesn't help me calculate a continuous offset for a phone cooling down degree by degree. Is there any public API, or even a proxy metric, that can give me a rough battery or internal temperature integer? I don’t need high resolution decimals. Just a general device temp to offset the hardware drift. Any undocumented tricks or proxy metrics anyone has used to handle this?

We're trying to create 26.4 beta and RC VMs on 15.x and 26.3 host OS' without success. We see Tue Mar 17 17:27:36 40 anka.log (install) 45803: failed to install macOS: Error Domain=VZErrorDomain Code=10006 "Installation requires a software update." UserInfo={NSLocalizedFailure=A software update is required to complete the installation., NSLocalizedFailureReason=Installation requires a software update.} Yet, if we create it the same way on 26.4 beta host OS, it works. We've tried the usual tricks of installing latest Xcode and preparing it (accepting license, etc). But, they don't work on 26.3 and 15.x. What's the trick to get the creation of 26.4 to work on <= 26.3 host OS?

System-wide deadlock in removexattr from revisiond / APFS We're experiencing a deadlock on certains systems when our software is installed, which is causing side effects in our process (and likely others) such as blocked queues and increased memory usage. According to the spindump, revisiond appears to be holding an exclusive lock within the kernel. Process: revisiond [426] UUID: 5E9B9E04-984B-31AD-A4FF-A1A90B7D53A1 Path: /System/Library/PrivateFrameworks/GenerationalStorage.framework/Versions/A/Support/revisiond Codesigning ID: com.apple.revisiond Shared Cache: 25AE5A2A-FE2A-3998-8D4E-F3C5C6E6CEB6 slid base address 0x189834000, slide 0x9834000 (System Primary) Architecture: arm64e Parent: launchd [1] UID: 0 Sudden Term: Tracked Memory Limit: 50MB Jetsam Priority: 40 Footprint: 6225 KB Time Since Fork: 1740319s Num samples: 940 (1-940) Num threads: 5 Note: 1 idle work queue thread omitted [...] Thread 0xc0616d 940 samples (1-940) priority 46 (base 4) last ran 241692.754s ago 940 start_wqthread + 8 (libsystem_pthread.dylib + 7068) [0x189d0ab9c] 940 _pthread_wqthread + 292 (libsystem_pthread.dylib + 11852) [0x189d0be4c] 940 _dispatch_workloop_worker_thread + 692 (libdispatch.dylib + 85356) [0x189b65d6c] 940 _dispatch_root_queue_drain_deferred_wlh + 292 (libdispatch.dylib + 87156) [0x189b66474] 940 _dispatch_lane_invoke + 440 (libdispatch.dylib + 45048) [0x189b5bff8] 940 _dispatch_lane_serial_drain + 944 (libdispatch.dylib + 42420) [0x189b5b5b4] 940 _dispatch_client_callout + 16 (libdispatch.dylib + 113364) [0x189b6cad4] 940 _dispatch_call_block_and_release + 32 (libdispatch.dylib + 7004) [0x189b52b5c] 940 ??? (revisiond + 168768) [0x10494d340] 940 ??? (revisiond + 165940) [0x10494c834] 940 ??? (revisiond + 40264) [0x10492dd48] 940 ??? (revisiond + 56680) [0x104931d68] 940 <patched truncated backtrace> 940 removexattr + 8 (libsystem_kernel.dylib + 23768) [0x189cd1cd8] *940 ??? (kernel.release.t6000 + 15240) [0xfffffe000886fb88] *940 ??? (kernel.release.t6000 + 1886348) [0xfffffe0008a3888c] *940 ??? (kernel.release.t6000 + 7730436) [0xfffffe0008fcb504] *940 ??? (kernel.release.t6000 + 2759592) [0xfffffe0008b0dba8] *940 ??? (kernel.release.t6000 + 2808244) [0xfffffe0008b199b4] *940 apfs_vnop_removexattr + 1044 (apfs + 474512) [0xfffffe000be8d4d0] *940 decmpfs_cnode_set_vnode_state + 80 (kernel.release.t6000 + 2945816) [0xfffffe0008b3b318] *940 IORWLockWrite + 184 (kernel.release.t6000 + 496184) [0xfffffe00088e5238] *940 ??? (kernel.release.t6000 + 494624) [0xfffffe00088e4c20] *940 ??? (kernel.release.t6000 + 619452) [0xfffffe00089033bc] *940 ??? (kernel.release.t6000 + 624472) [0xfffffe0008904758] The bulk of the other processes are waiting for that lock. (suspended, blocked by krwlock for reading owned by revisiond [426] thread 0xc0616d) (blocked by krwlock for writing owned by revisiond [426] thread 0xc0616d) Around the time of the event, these messages were logged by revision: 2026-03-06 18:49:37.781673-0500 0x16b7 Error 0x7f92f364 426 14 revisiond: [com.apple.revisiond:default] [ERROR] CSCopyChunkIDsForToken failed for 41639 2026-03-06 18:49:37.781716-0500 0x16b7 Error 0x7f92f365 426 14 revisiond: [com.apple.revisiond:default] [ERROR] updateEntry for new entry <private> failed 2026-03-06 18:49:37.781738-0500 0x16b7 Error 0x7f92f366 426 14 revisiond: [com.apple.revisiond:default] [ERROR] no entry for '<private>' 2026-03-06 18:49:37.781754-0500 0x16b7 Error 0x7f92f367 426 14 revisiond: [com.apple.revisiond:default] [ERROR] failed assembleInfoForOffset for fsid 16777234 fileid 359684022 offset 0 size 14334 (path <private>) Our agent uses Endpoint Security Framework to monitor events, and provide anti-tamper functionality for installed components and processes. While several EndpointSecurity calls appear in the spindump stack traces, we don't have any evidence that any calls from revisiond were blocked. What we'd really like to to understand what that lock is (appears to be decompressing an object on an APFS volume), what revisiond and APFS are doing with it, and what might cause it to deadlock. Of note, one of our processes is also waiting on that lock, one thread for reading and the other for writing. This issue affects machines running several macOS versions (15.x, 26.x). The machine in the examples is running macOS 26.3 (25D125)

Problem: custom icons for folder aliases not showing System drive and external drive custom alias folder icons don't showup on desktop or external drive (OS14.6 Sonoma 2023); they only show-up as plain folders or with an odd document icon. Alias doesn't connect to image; however it's there, easily accessible via spacebar. Finder doesn't save the custom icon to the alias. See below for workaround. Summary: I have custom alias icons on my desktop linking to their source files on the system drive and external drive.. however they do not display the custom icon. After upgrading from OS10.14 Mojave to OS14.6 Sonoma 2023, system drive & external drive custom alias icons no longer display the icon on either drive (there is a work-around for Mojave; see history section). Personal impact: hampered file navigation and workflow; I'm lost, can't tell where anything is; not having my icons makes it especially difficult to navigate my files and hampers my workflow significantly. Desired outcome: all custom icons for folder aliases linking to source files (on system & external drives) appear on the desktop, and in all directories on system & external drives (including encrypted external drives). Status.. August 2024: called apple support, they said there is no solution, and there are no plans to fix it, and no plans for a fix in OS 15 Sequoia (in public beta now) Action: ❯ leave feedback at https://www.apple.com/feedback/macos/ ❯ join this campaign to fix this once and for all! -- After 20 years of dealing with this issue.. we need to fix this. History: ▪ OS 10.14 Mojave 2018: external drive alias icons don't work; because upon startup, the icon images for these files disappear; because when system starts it loads the system drive icons but not the external drive icons because it's password protected, hence icon information does not get loaded; alias icons can't connect with unmounted external drive @ boot; however it's there, easily accessible via spacebar the FIX: alias the icons on the desktop each time after boot, however the names are altered ▪ OS X 10.11 El Cap 2015: drag the icons to a folder then back to desktop.. sometimes this works I stayed on OS9 as long as possible because of the OS10 icon problem ▪ OS 9: all custom alias folder icons worked fine Givens: space bar has fast access to icon -highlight alias and press space bar -- seems that it would be a simple solution, since the image is there -- get info for alias also has the image in preview How to make a custom icon: open a pic (typically from a screenshot; .png), select image with cursor with shift key down (for a perfect square), copy ⌘C, click target folder, get info ⌘I, click on folder icon on top left corner, paste ⌘V Fix -- How? --make a solution approach for a macOS dev? some bash process to link to icon; how to access icon Swift? process to renew the alias icon process goes through all desktop icons.. fixes them; new icon, correct name routine where all icons on desktop link to their files easily making a new alias.. as easy as making a regular alias; cammand L, etc make alias search for the image app that makes alias create custom desktop.. a GUI w links -- INTERIM FIX / WORKAROUND create a new folder on your desktop, name it, place it's alias inside the folder, fix the icon, when you open the desktop folder, you will then have to click on the alias --this is very time-consuming and tedious note: there may be easier options for OSs prior to Sonoma; review History section workflow: symbol note: ⇧ shift, ⌃ control, ⌥ option, ⌘ cammand create new folder on desktop ⌘⇧N , name it.. if the name is already taken by the alias, change the alias's name; for example.. alias it ⌘^A click on this new folder then ⌘I (get info) click on the alias, open source location ⌘R (or ⌘⌥^A on older OSs), click on source file (if not highlighted) then ⌘I (get info) , click on folder icon on top left corner, copy ⌘C click on the get-info window you opened for the new folder, click on folder icon on top left corner, paste ⌘V (if not working see ¹ below), close each of these windows with ⌘W place the associated aliased folder into the new folder you can also do this in groups of folders (3-6 seems is optimal).. for example.. move 3 alias icons to clear area on desktop, create 3 new folders and place them below the aliases, select all aliases and ⌘C, open a text document and ⌘V, fix names & name new folders, select new folders, ⌘I, select target aliases, ⌘R, ⌘I for each, move the alias windows below the new folder windows, copy/paste icons from source to new file, close these windows, place alias folders into new folders ¹ if paste function not working.. move on to the next folder and come back.. it can be moody, if it's not working at all.. restart the computer note2: some icons now have a yellow streak at the bottom let us know if you have any solutions or workarounds, or can code this (provide a script or app)

We are seeing an issue after updating iPads to iPadOS 26.4 where cellular service is lost until network settings are reset. Environment: Devices managed via Apple Business Manager and Microsoft Intune Carrier: Verizon Confirmed affected devices: iPad (9th generation) eSIM Behavior: After update, device shows no cellular service No prompt to re-activate or re-add the cellular plan The plan appears to still be present on the device Workaround observed: Resetting Network Settings restores service Notes: This does not appear to be a provisioning issue (no need to re-add eSIM) Behavior suggests the cellular/eSIM state may not be initializing correctly after update Toggling Cellular or Airplane mode has not yet been tested for service restoration. We have not yet confirmed whether devices using a physical SIM are affected Still gathering data on scope across additional iPad models Additional observation: We have not observed this behavior on iPhones (e.g., iPhone 16 on iOS 26.4 with LTE remains unaffected) Has anyone else observed similar behavior on iPadOS 26.4, particularly on managed devices or eSIM configurations?

Hello, How does macOS handle coexistence between multiple Transparent Proxy providers from different vendors if their network rules overlap and one provider modifies the traffic? Thank you in advance!

Hello, Is it possible for a Network Extension (running in its sandbox) to act as a client for an XPC service hosted by a Launch Daemon (e.g., to offload data processing)? Are there any specific sandbox restrictions or entitlement requirements for this type of XPC communication? Thank you in advance!

The M5 Pro does not connect to the Wi-Fi AP using RADIUS when NetworkExtension Activiate. The M1 and M2 Pro worked, but only the M5 Pro MacBook Pro did not work. If you deactivate NetworkExtension, it connects to the AP, and afterwards, it works even if you activate NetworkExtension.

Testing copyfile on a folder on an external volume (which takes a bit a of time) I'm running into an issue where copyfile gets to the end of the operation and then just fails. In the callback I can see that the failure occurs on a .DS_Store file inside the folder. So for a .DS_Store it is simple enough for me to just ignore the error and return COPYFILE_SKIP but the somewhat more concerning issue here is that the true error reason is seemingly not reported? In the callback if I read errno it is 0. When copyfile returns it returns -1 after I return COPYFILE_QUIT (and errno is 0) so I don't know what the error is or the appropriate way to handle it. For .DS_Store just skipping seems reasonable but when copying a folder it may be appropriate to get the true failure reason. But checking the last path component of source path seems like a hack way to handle errors. If a file in the copying folder with important user data I can't just silently skip it - it isn't clear to me how I should properly proceed in a situation where I can't get the actual reason for the failure.

A user of my app reported that when my app copies files from a QNAP NAS to a folder on their Mac, they get the error "Result too large". When copying the same files from the Desktop, it works. I asked them to reproduce the issue with the sample code below and they confirmed that it reproduces. They contacted QNAP for support who in turn contacted me saying that they are not sure they can do anything about it, and asking if Apple can help. Both the app user and QNAP are willing to help, but at this point I'm also unsure how to proceed. Can someone at Apple say anything about this? Is this something QNAP should solve, or is this a bug in macOS? P.S.: I've had users in the past who reported the same issue with other brands, mostly Synology. import Cocoa @main class AppDelegate: NSObject, NSApplicationDelegate { func applicationDidFinishLaunching(_ aNotification: Notification) { let openPanel = NSOpenPanel() openPanel.canChooseDirectories = true openPanel.runModal() let source = openPanel.urls[0] openPanel.canChooseFiles = false openPanel.runModal() let destination = openPanel.urls[0] do { try copyFile(from: source, to: destination.appendingPathComponent(source.lastPathComponent, isDirectory: false)) } catch { NSAlert(error: error).runModal() } NSApp.terminate(nil) } private func copyFile(from source: URL, to destination: URL) throws { if try source.resourceValues(forKeys: [.isDirectoryKey]).isDirectory == true { try FileManager.default.createDirectory(at: destination, withIntermediateDirectories: false) for source in try FileManager.default.contentsOfDirectory(at: source, includingPropertiesForKeys: nil) { try copyFile(from: source, to: destination.appendingPathComponent(source.lastPathComponent, isDirectory: false)) } } else { try copyRegularFile(from: source, to: destination) } } private func copyRegularFile(from source: URL, to destination: URL) throws { let state = copyfile_state_alloc() defer { copyfile_state_free(state) } var bsize = UInt32(16_777_216) if copyfile_state_set(state, UInt32(COPYFILE_STATE_BSIZE), &bsize) != 0 { throw NSError(domain: NSPOSIXErrorDomain, code: Int(errno)) } else if copyfile_state_set(state, UInt32(COPYFILE_STATE_STATUS_CB), unsafeBitCast(copyfileCallback, to: UnsafeRawPointer.self)) != 0 { throw NSError(domain: NSPOSIXErrorDomain, code: Int(errno)) } else if copyfile(source.path, destination.path, state, copyfile_flags_t(COPYFILE_DATA | COPYFILE_SECURITY | COPYFILE_NOFOLLOW | COPYFILE_EXCL | COPYFILE_XATTR)) != 0 { throw NSError(domain: NSPOSIXErrorDomain, code: Int(errno)) } } private let copyfileCallback: copyfile_callback_t = { what, stage, state, src, dst, ctx in if what == COPYFILE_COPY_DATA { if stage == COPYFILE_ERR { return COPYFILE_QUIT } } return COPYFILE_CONTINUE } }

I'm writing a read-only filesystem extension. I see that the documentation for loadResource(resource:options:replyHandler:) claims that the --rdonly option is supported, which suggests that this should be possible. However, I have never seen this option provided to my filesystem extension, even if I return usableButLimited as a probe result (where it doesn't mount at all - FB19241327) or pass the -r or -o rdonly options to the mount(8) command. Instead I see those options on the volume's activate call. But other than saving that "readonly" state (which, in my case, is always the case) and then throwing on all write-related calls I'm not sure how to actually mark the filesystem as "read-only." Without such an indicator, the user is still offered the option to do things like trash items in Finder (although of course those operations do not succeed since I throw an EROFS error in the relevant calls). It also seems like the FSKit extensions that come with the system handle read-only strangely as well. For example, for a FAT32 filesystem, if I mount it like mount -r -F -t msdos /dev/disk15s1 /tmp/mnt Then it acts... weirdly. For example, Finder doesn't know that the volume is read-only, and lets me do some operations like making new folders, although they never actually get written to disk. Writing may or may not lead to errors and/or the change just disappearing immediately (or later), which is pretty much what I'm seeing in my own filesystem extension. If I remove the -F option (thus using the kernel extension version of msdos), this doesn't happen. Are read-only filesystems currently supported by FSKit? The fact that extensions like Apple's own msdos also seem to act weirdly makes me think this is just a current FSKit limitation, although maybe I'm missing something. It's not necessarily a hard blocker given that I can prevent writes from happening in my FSKit module code (or, in my case, just not implement such features at all), but it does make for a strange experience. (I reported this as FB21068845, although I'm mostly asking here because I'm not 100% sure this is not just me missing something.)

Hi, I am developing instant snapshot backup solution for macOS using Endpoint Security. We have stumbled upon a Kernel Panic when using "fclonefileat" API. We are catching a kernel panic on customer machines when attempting to clone the file during ES sync callback: panic(cpu 0 caller 0xfffffe002c495508): "apfs_io_lock_exclusive : Recursive exclusive lock attempt" @fs_utils.c:435 I have symbolized the backtrace to know it is related to clone operation with the following backtrace: apfs_io_lock_exclusive apfs_clone_internal apfs_vnop_clonefile I made a minimal repro that boils down to the following operations: apfs_crash_stress - launch thread to do rsrc writes static void *rsrc_write_worker(void *arg) { int id = (int)(long)arg; char buf[8192]; long n = 0; fill_pattern(buf, sizeof(buf), 'W' + id); while (n < ITERATION_LIMIT) { int file_idx = n % NUM_SOURCE_FILES; int fd = open(g_src_rsrc[file_idx], O_WRONLY | O_CREAT, 0644); if (fd >= 0) { off_t off = ((n * 4096) % RSRC_DATA_SIZE); pwrite(fd, buf, sizeof(buf), off); if ((n & 0x7) == 0) fsync(fd); close(fd); } else { setxattr(g_src[file_idx], "com.apple.ResourceFork", buf, sizeof(buf), 0, 0); } n++; } printf("[rsrc_wr_%d] done (%ld ops)\n", id, n); return NULL; } apfs_crash_es - simple ES client that is cloning the file (error checking omitted for brevity) static std::string volfsPath(uint64_t devId, uint64_t vnodeId) { return "/.vol/" + std::to_string(devId) + "/" + std::to_string(vnodeId); } static void cloneAndScheduleDelete(const std::string& sourcePath, dispatch_queue_t queue, uint64_t devId, uint64_t vnodeId) { struct stat st; if (stat(sourcePath.c_str(), &st) != 0 || !S_ISREG(st.st_mode)) return; int srcFd = open(sourcePath.c_str(), O_RDONLY); const char* cloneDir = "/Users/admin/Downloads/_clone"; mkdir(cloneDir, 0755); const char* filename = strrchr(sourcePath.c_str(), '/'); filename = filename ? filename + 1 : sourcePath.c_str(); std::string cloneFilename = std::string(filename) + ".clone." + std::to_string(time(nullptr)) + "." + std::to_string(getpid()); std::string clonePath = std::string(cloneDir) + "/" + cloneFilename; fclonefileat(srcFd, AT_FDCWD, clonePath.c_str(), 0); { dispatch_after(dispatch_time(DISPATCH_TIME_NOW, 1 * NSEC_PER_SEC), queue, ^{ if (unlink(clonePath.c_str()) == 0) { LOG("Deleted clone: %s", clonePath.c_str()); } else { LOG("Failed to delete clone: %s", clonePath.c_str()); } }); } close(srcFd); } static const es_file_t* file(const es_message_t* msg) { switch (msg->event_type) { case ES_EVENT_TYPE_AUTH_OPEN: return msg->event.open.file; case ES_EVENT_TYPE_AUTH_EXEC: return msg->event.exec.target->executable; case ES_EVENT_TYPE_AUTH_RENAME: return msg->event.rename.source; } return nullptr; } int main(void) { es_client_t* cli; auto ret = es_new_client(&cli, ^(es_client_t* client, const es_message_t * msgc) { if (msgc->process->is_es_client) { es_mute_process(client, &msgc->process->audit_token); return respond(client, msgc, true); } dispatch_async(esQueue, ^{ bool shouldClone = false; if (msgc->event_type == ES_EVENT_TYPE_AUTH_OPEN) { auto& ev = msgc->event.open; if (ev.fflag & (FWRITE | O_RDWR | O_WRONLY | O_TRUNC | O_APPEND)) { shouldClone = true; } } else if (msgc->event_type == ES_EVENT_TYPE_AUTH_UNLINK || msgc->event_type == ES_EVENT_TYPE_AUTH_RENAME) { shouldClone = true; } if (shouldClone) { if (auto f = ::file(msgc)) cloneAndScheduleDelete(f->path.data, cloneQueue, f->stat.st_dev, f->stat.st_ino); } respond(client, msgc, true); }); }); LOG("es_new_client -> %d", ret); es_event_type_t events[] = { ES_EVENT_TYPE_AUTH_OPEN, ES_EVENT_TYPE_AUTH_EXEC, ES_EVENT_TYPE_AUTH_RENAME, ES_EVENT_TYPE_AUTH_UNLINK, }; es_subscribe(cli, events, sizeof(events) / sizeof(*events)); } Create 2 terminal sessions and run the following commands: % sudo ./apfs_crash_es % sudo ./apfs_crash_stress ~/Downloads/test/ Machine will very quickly panic due to APFS deadlock. I expect that no userspace syscall should be able to cause kernel panic. It looks like a bug in APFS implementation and requires fix on XNU/kext side. We were able to reproduce this issue on macOS 26.3.1/15.6.1 on Intel/ARM machines. Here is the panic string: panic_string.txt Source code without XCode project: apfs_crash_es.cpp apfs_crash_stress.cpp Full XCode project + full panic is available at https://www.icloud.com/iclouddrive/0f215KkZffPOTLpETPo-LdaXw#apfs%5Fcrash%5Fes

I want to write a CryptoTokenKit plugin to be used to unlock FileVault. I understand macOS already provides such a plugin for a PIV smart card https://support.apple.com/en-mz/guide/deployment/dep806850525/web Perfect. I want to do the same for a non-PIV smart card. So I have to provide my own CryptoTokenKit plugin. I already implemented a smart card plugin TKSmartCardToken. I can use it so pair the user with the smart card and use the smart card to login (except for the 1st login when the disk is still encrypted). As far as I understand for preboot I need to provide a "persistent token" https://support.apple.com/en-mz/guide/deployment/dep4e2622249/web From Xcode I created an empty application, and added a "Persistent Token Extension" (instead of a "Smart Card Token Extension"). After built I can see my new token in the output of "pluginkit -m -p com.apple.ctk-tokens". My questions: how and when is my plugin loaded? I added calls to os_log_error() in all the empty methods created by the Xcode template but I do not find my log messages in the console Apple provides a sample code for an old (2016) PIV token in https://developer.apple.com/library/archive/samplecode/PIVToken/Introduction/Intro.html Is the source code of the PIV token used at pre-boot also available? Thanks

Platform: macOS 26.3.1, M5 Pro MacBook Pro Framework: CoreWLAN Affected applications: NetViews, Air Tool 2, and our own tooling — appears to be specific to the new Wi-Fi 7 hardware Hardware Card Type: chip id: 0x11 api 1.2 firmware [Rev 72.11.260 N1B1 devFused=0] phy [17.1.17.0], core80211 [324.10.260 N1_silicon_b] Firmware: Jan 27 2026 21:18:32 version XBS_BUILD_TAG GIT_DESCRIBE FWID chip id: 0x11 api 1.2 firmware [Rev 72.11.260 N1B1 devFused=0] phy [17.1.17.0], core80211 [324.10.260 N1_silicon_b] Driver: IO80211_driverkit-1540.16 "IO80211_driverkit-1540.16" Jan 27 2026 Background Both issues described below were working correctly on macOS 26 with previous-generation hardware. The regression is specific to the Wi-Fi 7 card shipping in the M5 Pro MacBook Pro. This is not an OS regression — it is a hardware/driver/firmware compatibility issue with the new card under macOS 26. Issue 1: disassociate() + tcpdump/Wireshark -I no longer enters monitor mode Previously, the standard approach of calling disassociate() and then launching tcpdump -i en0 -I or Wireshark -i en0 -I -k would successfully put the interface into monitor mode. On the M5 Pro Wi-Fi 7 card, this no longer works. The capture tool launches but the interface either stays in station mode or enters mode 0 - where there is no connection, but still not able to be a monitor radio. This is the primary regression affecting third-party wireless tools. Issue 2: setWLANChannel reports success but the radio only retunes once As a workaround for Issue 1, we use the built-in Wireless Diagnostics → Sniffer tool to establish monitor mode (which works fairly reliably on this hardware). Once the interface is in monitor mode via that path, we attempt to change the channel using setWLANChannel: let iface = CWWiFiClient.shared().interface(withName: "en0")! let target = iface.supportedWLANChannels()! .first { $0.channelNumber == 6 && $0.channelWidth == .width20MHz }! try iface.setWLANChannel(target) The first call succeeds (eg: channel 48 -> 6) the radio actually tunes to the requested channel and Wireshark captures frames there. Any subsequent call (eg: channel 48 -> 6 -> 1) shows the same apparent success - no error thrown, wlanChannel() updates to reflect the new channel - but the radio does not retune. Wireshark continues capturing on the first changed channel. We have tested with disassociate() and interface power cycling between attempts — neither resets the ability to retune the radio. What we have ruled out Timing: delays between calls make no difference Competing processes holding the interface wlanChannel() returning a stale cache value — it updates correctly, but diverges from actual hardware state after the first channel change Key data point: Wireless Diagnostics Sniffer works The built-in Wireless Diagnostics → Sniffer tool successfully puts the interface into monitor mode on this hardware. This confirms the card and driver are capable - the issue is that the capability is no longer reachable via CoreWLAN or via tcpdump/Wireshark's -I flag. Wireless Diagnostics Sniffer does not support live channel changes, so it cannot serve as a full workaround. The questions Is there a supported path for third-party apps to enter monitor mode on the new Wi-Fi 7 hardware on macOS 26? What is the correct mechanism for changing channels while in monitor mode - is setWLANChannel expected to retune the radio on subsequent calls, or is there a different API intended for this? The fact that Wireless Diagnostics accomplishes both (albeit, not live) confirms the hardware and driver are fully capable - we are looking for the sanctioned equivalent for third-party tools.

Hello! currently I got a massive issue after upgrading all 10.000 Macs from macOS 26.3 to 26.3.1 or 26.4 and running some programs/apps on it which are currently not running because we need to read out the Hardware UUID. After the Update to macOS 26.3.1 and 26.4 the Terminal for the command system_profiler SPHardwareDataType is return an additional line: % system_profiler SPHardwareDataType 2026-03-25 11:28:17.939 system_profiler[73588:434733] hw.cpufamily: 0x1b588bb3 Hardware: bevor the Update the response was: %system_profiler SPHardwareDataType Hardware: Why I am getting this extra line "2026-03-25 11:28:17.939 system_profiler[73588:434733] hw.cpufamily: 0x1b588bb3" with a timestamp and system_profilder + hw.cpufamily as response? How can I disable this? Also the difference is with the command: system_profiler -json SPHardwareDataType Above version macOS 26.3.1 I will get an percentage sign in the Output - this is not a valid json! ...(shorten)    }   ] }%   on macOS version 26.3 and lower the response is: ...(shorten)      }   ] }

I am working on a cross-platform application where, on Android and Windows, I explicitly load dynamic libraries at runtime (e.g., LoadLibrary/GetProcAddress on Windows and equivalent mechanisms on Android). This allows me to control when and how modules are loaded, and to transfer execution flow from the main executable into the dynamically loaded library. I want to follow a similar approach on macOS (and also iOS) and explicitly load a framework (instead of relying on implicit linking via import). From my exploration so far, I have come across the following options: Using Bundle (NSBundle) - Load framework using: let bundle = Bundle(path: path) try bundle?.load() Access functionality via NSPrincipalClass and @objc methods (class-based entry) Using dlopen + dlsym Load the framework binary and resolve symbols: let handle = dlopen(path, RTLD_NOW) let sym = dlsym(handle, "EntryPoint") Expose Swift functions using @_cdecl Using a hybrid approach (Bundle + dlsym) - Use Bundle for loading and dlsym for symbol access From what I understand: Bundle works well for class-based/plugin-style designs using the Objective-C runtime while dlopen/dlsym works at the symbol level and is closer to what I am doing on other platforms However, my requirement is specifically: Explicit runtime loading (not compile-time linking) Ability to transfer execution flow from the main executable into the dynamically loaded framework **What is the recommended approach on macOS for this kind of explicit dynamic loading, or is implicit loading the way to go? Also, would it differ for interactive and non-interactive apps? ** In what scenarios would Apple recommend using Bundle instead of dlopen? Is there any other methods best for this explicit loading of frameworks on Apple?

I created two sample apps — one sandboxed and one non‑sandboxed. I tested reading Managed Preferences using bash commands, CFPreferencesCopyValue for a domain, and defaults read. Everything works correctly only when the sandbox is disabled in the entitlements. When the sandbox is enabled, I’m unable to read values from /Library/Managed Preferences/. Is there any supported way for a sandboxed macOS app to read an MDM-delivered preference plist under /Library/Managed Preferences/? Any guidance on the correct and Apple‑supported method would be appreciated.

After building the sample and enabling the file system extension the mount command is freezing. Any tips how to diagnose that? The logs show the following: log stream --style compact --info --debug --predicate 'subsystem == "com.apple.FSKit" OR process CONTAINS[c] "samplecode"' Filtering the log data using "subsystem == "com.apple.FSKit" OR process CONTAINS[c] "samplecode"" Timestamp Ty Process[PID:TID] 2026-03-17 15:15:51.832 I mount[16111:d88caa] [com.apple.FSKit:default] FSClient setting up connection to fskitd 2026-03-17 15:15:51.833 Db fskitd[589:d88a5f] [com.apple.FSKit:default] -[liveFilesMountServiceDelegate listener:shouldAcceptNewConnection:]: start 2026-03-17 15:15:51.833 Df fskitd[589:d88a5f] [com.apple.FSKit:default] Incomming connection, entitled 0 2026-03-17 15:15:51.833 Db fskitd[589:d88a5f] [com.apple.FSKit:default] -[liveFilesMountServiceDelegate listener:shouldAcceptNewConnection:]: accepting connection 2026-03-17 15:15:51.833 Df fskitd[589:d88a5f] [com.apple.FSKit:default] Hello FSClient! entitlement no 2026-03-17 15:15:51.834 Df mount[16111:d88caa] [com.apple.FSKit:default] Setting remote protocol to all XPC 2026-03-17 15:15:51.834 Df fskitd[589:d88a5f] [com.apple.FSKit:default] About to get current agent for 501 2026-03-17 15:15:51.834 I fskitd[589:d88a5f] [com.apple.FSKit:default] About to call to fskit_agent 2026-03-17 15:15:51.835 I fskit_agent[10123:d877d9] [com.apple.FSKit:default] Getting extensions 2026-03-17 15:15:51.836 Db fskitd[589:d88a5f] [com.apple.FSKit:default] -[fskitdAgentManager currentExtensionForShortName:auditToken:replyHandler:]_block_invoke: Found extension for fsShortName () 2026-03-17 15:15:51.837 I fskitd[589:d88a5f] [com.apple.FSKit:default] Probe starting on 2026-03-17 15:15:51.837 Db fskitd[589:d87c31] [com.apple.FSKit:default] -[FSResourceManager getResourceState:]:found: 2026-03-17 15:15:51.837 Db fskitd[589:d87c31] [com.apple.FSKit:default] -[FSResourceManager addTaskUUID:resource:]:: Adding task () 2026-03-17 15:15:51.837 Df fskitd[589:d87c31] [com.apple.FSKit:default] About to get current agent for 501 2026-03-17 15:15:51.837 I fskitd[589:d87c31] [com.apple.FSKit:default] About to call to fskit_agent 2026-03-17 15:15:51.837 I fskit_agent[10123:d877d9] [com.apple.FSKit:default] Getting extensions 2026-03-17 15:15:51.838 Db fskitd[589:d87c31] [com.apple.FSKit:default] -[fskitdXPCServer getExtensionModuleFromID:forToken:]_block_invoke: Found extension , attrs 2026-03-17 15:15:51.838 Db fskitd[589:d87c31] [com.apple.FSKit:default] applyResource starting with resource kind 4

We are trying to determine whether a third-party DriverKit HID dext can seize or intercept raw HID input reports from an external mouse through any top case–related path in the HID stack. Our dext is based on IOUserHIDEventDriver, and the goal is to receive raw input reports before they are translated into higher-level pointer events. Apple’s public HIDDriverKit documentation describes IOUserHIDEventDriver as the driver object responsible for dispatching pointer, digitizer, scrolling, and related HID-originated events, but it is not clear to us whether any “top case” path is actually exposed or supported for third-party matching in DriverKit. What we want to clarify is specifically about external mouse devices, not the built-in trackpad itself. Questions: Is there any officially supported way for a third-party DriverKit HID dext to bind through a top case–related path and receive raw HID input reports from an external mouse? Is “top case” something that third-party DriverKit drivers can meaningfully target for matching/attachment, or is it only an internal Apple implementation detail? If such a path exists, can it be used to seize raw reports before they are converted into higher-level pointer events? If not, what is the officially supported boundary for third-party DriverKit access to raw reports from external mouse-class HID devices? To be clear, we are not asking about synthesizing pointer events. We are asking whether a third-party DriverKit dext can directly observe or seize the original HID input reports from an external mouse by attaching through any top case–related portion of the HID stack. If “top case” is not a public DriverKit concept that third parties can target, confirmation of that would also be very helpful.