Debugging

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SendProcessControlEvent:toPid: encountered an error
iPhone 16.0 16.0.2 系统上运行小组件出现问题, 其他系统没有问题 SendProcessControlEvent:toPid: encountered an error: Error Domain=com.apple.dt.deviceprocesscontrolservice Code=8 "Failed to show Widget 'com.jiduauto.iphone.jdcomiphoneWidget' error: Error Domain=FBSOpenApplicationServiceErrorDomain Code=5 "The request to open "com.apple.springboard" failed." UserInfo={NSLocalizedDescription=The request to open "com.apple.springboard" failed., NSLocalizedFailureReason=Unexpected error type., NSUnderlyingError=0x600002bbd7a0 {Error Domain=BSServiceConnectionErrorDomain Code=3 "XPC error received on message reply handler" UserInfo={BSErrorCodeDescription=OperationFailed, NSLocalizedFailureReason=XPC error received on message reply handler}}, BSErrorCodeDescription=InvalidResponse}." UserInfo={NSLocalizedDescription=Failed to show Widget 'com.jiduauto.iphone.jdcomiphoneWidget' error: Error Domain=FBSOpenApplicationServiceErrorDomain Code=5 "The request to open "com.apple.springboard" failed." UserInfo={NSLocalizedDescription=The request to open "com.apple.springboard" failed., NSLocalizedFailureReason=Unexpected error type., NSUnderlyingError=0x600002bbd7a0 {Error Domain=BSServiceConnectionErrorDomain Code=3 "XPC error received on message reply handler" UserInfo={BSErrorCodeDescription=OperationFailed, NSLocalizedFailureReason=XPC error received on message reply handler}}, BSErrorCodeDescription=InvalidResponse}., NSUnderlyingError=0x600002bbd5f0 {Error Domain=FBSOpenApplicationServiceErrorDomain Code=5 "The request to open "com.apple.springboard" failed." UserInfo={NSLocalizedDescription=The request to open "com.apple.springboard" failed., NSLocalizedFailureReason=Unexpected error type., NSUnderlyingError=0x600002bbd7a0 {Error Domain=BSServiceConnectionErrorDomain Code=3 "XPC error received on message reply handler" UserInfo={BSErrorCodeDescription=OperationFailed, NSLocalizedFailureReason=XPC error received on message reply handler}}, BSErrorCodeDescription=InvalidResponse}}} Domain: DTXMessage Code: 1 User Info: { DVTErrorCreationDateKey = "2024-02-19 08:02:14 +0000"; } System Information macOS Version 13.5.2 (Build 22G91) Xcode 15.0 (22265) (Build 15A240d) Timestamp: 2024-02-19T16:02:14+08:00
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1.7k
Nov ’25
Can an IP address manually be entered into Xcode to wirelessly connect to an iOS device?
I often use a Wi-Fi network where: Whatever mechanism Xcode uses to automatically discover a previously paired iOS device seems to be blocked (the Devices and Simulators window shows "Browsing on the local area network for [iPhone]" and never proceeds), but I can connect to the iOS device from my Mac if I know its IP address, such as by pinging it The same hardware/software configuration works with wireless Xcode connections on a different Wi-Fi network. Thus I'm wondering if there's any functionality that allows the IP address to be manually entered into Xcode to avoid needing to connect a cable from my Mac to my iPhone during development. Searching around seems to suggest this existed at some point in the past but I can no longer find this in a current version of Xcode. Or if there are any other workarounds, although I can't modify the network itself as it's not my network.
2
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291
Nov ’25
Keyword not working
The Center for Innovation in Education created a reading program designed to teach every single child to read, regardless of any supposed difficulty in learning. The Center conducted a ten-year study of its Reading Program’s effectiveness. Over those ten years, the Center placed 2,048 Reading Program kits in classrooms across America. More than 300,000 children took part in the Center’s study. Results: The Reading Program taught every single child to read in every single classroom, every single year, regardless of any child’s supposed reading readiness - including dyslexic, autistic, and even Down syndrome children. No failures then or in any of the many years that have followed. Despite the Program’s success, educational publishers refused to publish it. Their refusals will be explained and hopefully counteracted in a book that is scheduled to be published in 2026. In response to publishers’ refusal to make the program available, the Center made it available as a free download from its website. The Center also made its program available as 14 free iPad apps. While the apps can be searched for individually by their unique names, since the apps are interrelated and meant to complement one another, the first keyword assigned to all 14 apps was the same. That same keyword is still in its first position for every app. The first keyword listed for each of the 14 apps is the word “Dekodiphukan”. That meant-to-be hard-to-read search word has worked well every year since the apps were introduced. However, in June of this year, that search term could find only 1 of the 14 apps. We reported this problem to Apple Support on June 26th. It is now November, and the problem remains unresolved. The only response we receive each time we ask for an update on the resolution of this problem the answer every time is: Reported search issues of this type require extensive review by Apple to determine whether it is valid and to confirm the appropriate action. There is no other response. No update has ever been sent to us. There is no phone number I can find to call. It was suggested to me by someone I spoke with in a different department at Apple Developers that I post my problem on the Developer Forum, in hopes that someone here can provide a suggestion for a way around this problem. Parents and teachers wishing to use our Reading Program with their children should not have to enter 14 different names to access our Reading Program.
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481
Nov ’25
Problem loading our login attempt indefinitely
Hi, I have an application published in the Marketplace. I made certain updates to the app. I did my tests.No problem. I did my tests via Testflight. There is no problem I encountered. But my app update request was returned by app review. The answer i got from them ;  "Specifically, our login attempt displayed loading indefinitely; we were unable to access the app features and functionality." Here are the ways that I tried and the app worked successfully. Connect from America using VPN.No problem, it works. I connected from using IPV6.No problem, it works. I tried with simulator.No problem, it works. I tried real device.No problem , it works. I tried testflight.No problem, it works. I tired version 15.2 and earlier.No problem , it works. I have no idea why apple staff are getting this error. Has anyone encountered such a problem before? What solutions would you suggest? I'm waiting for your help.
5
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902
Nov ’25
NSISSparseVectorAddTermWithPlaceValueCoefficientStartingIndex.cold.1 crash
Hi, We began to get this new crash in codes that exist years ago from our recent released version, it crashed after a view removed itself from superview. We tried to look at the assembly code of NSISSparseVectorAddTermWithPlaceValueCoefficientStartingIndex, find out that d0 <= 0 would branch to NSISSparseVectorAddTermWithPlaceValueCoefficientStartingIndex.cold.1. We believe that it's related with Autolayout, but setting a negative value for width or height constraints can't reproduce this crash. Here is the crash log Exception Type: NSInternalInconsistencyException Invalid parameter not satisfying: placeValue > 0 Exception Codes: fault addr: (null) Crashed Thread: 0 0 CoreFoundation ___exceptionPreprocess + 164 1 libobjc.A.dylib _objc_exception_throw + 88 2 Foundation -[NSMutableDictionary(NSMutableDictionary) initWithContentsOfFile:] + 0 3 CoreAutoLayout NSISSparseVectorAddTermWithPlaceValueCoefficientStartingIndex.cold.1 + 100 4 CoreAutoLayout _NSISSparseVectorAddTermWithPlaceValueCoefficientStartingIndex + 848 5 CoreAutoLayout _NSISSparseVectorAddVectorTimesScalar + 72 6 CoreAutoLayout -[NSISObjectiveLinearExpression replaceVar:withExpression:processVarNewToReceiver:processVarDroppedFromReceiver:] + 200 7 CoreAutoLayout ____substituteOutAllOccurencesOfBodyVar_block_invoke + 504 8 CoreAutoLayout __substituteOutAllOccurencesOfBodyVar + 340 9 CoreAutoLayout __pivotToMakeColNewHeadOfRow + 960 10 CoreAutoLayout -[NSISEngine removeConstraintWithMarker:] + 748 11 CoreAutoLayout -[NSLayoutConstraint _removeFromEngine:] + 140 12 UIKitCore ___57-[UIView(AdditionalLayoutSupport) _switchToLayoutEngine:]_block_invoke + 164 13 CoreAutoLayout -[NSISEngine withBehaviors:performModifications:] + 84 14 UIKitCore -[UIView(AdditionalLayoutSupport) _switchToLayoutEngine:] + 212 15 UIKitCore ___57-[UIView(AdditionalLayoutSupport) _switchToLayoutEngine:]_block_invoke_2 + 148 16 UIKitCore ___57-[UIView(AdditionalLayoutSupport) _switchToLayoutEngine:]_block_invoke + 544 17 CoreAutoLayout -[NSISEngine withBehaviors:performModifications:] + 84 18 UIKitCore -[UIView(AdditionalLayoutSupport) _switchToLayoutEngine:] + 212 19 UIKitCore ___45-[UIView(Hierarchy) _postMovedFromSuperview:]_block_invoke + 84 20 CoreAutoLayout -[NSISEngine withBehaviors:performModifications:] + 84 21 UIKitCore -[UIView _postMovedFromSuperview:] + 512 22 UIKitCore ___UIViewWasRemovedFromSuperview + 136 23 UIKitCore -[UIView(Hierarchy) removeFromSuperview] + 244 Assembly of NSISSparseVectorAddTermWithPlaceValueCoefficientStartingIndex CoreAutoLayout`NSISSparseVectorAddTermWithPlaceValueCoefficientStartingIndex: -> 0x1ec1a2124 <+0>: pacibsp 0x1ec1a2128 <+4>: stp d11, d10, [sp, #-0x60]! 0x1ec1a212c <+8>: stp d9, d8, [sp, #0x10] 0x1ec1a2130 <+12>: stp x24, x23, [sp, #0x20] 0x1ec1a2134 <+16>: stp x22, x21, [sp, #0x30] 0x1ec1a2138 <+20>: stp x20, x19, [sp, #0x40] 0x1ec1a213c <+24>: stp x29, x30, [sp, #0x50] 0x1ec1a2140 <+28>: add x29, sp, #0x50 0x1ec1a2144 <+32>: mov x19, x1 0x1ec1a2148 <+36>: fmov d9, d2 0x1ec1a214c <+40>: fmov d10, d1 0x1ec1a2150 <+44>: fmov d8, d0 0x1ec1a2154 <+48>: mov x20, x0 0x1ec1a2158 <+52>: fcmp d0, #0.0 0x1ec1a215c <+56>: b.le 0x1ec1a2470 ; <+844> 0x1ec1a2160 <+60>: fcmp d10, #0.0 0x1ec1a2164 <+64>: adrp x8, 112778 .... 0x1ec1a2468 <+836>: ldp d11, d10, [sp], #0x60 0x1ec1a246c <+840>: retab 0x1ec1a2470 <+844>: bl 0x1ec1cac18 ; NSISSparseVectorAddTermWithPlaceValueCoefficientStartingIndex.cold.1 0x1ec1a2474 <+848>: b 0x1ec1a2160 ; <+60>
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171
Oct ’25
Apple Watch may need to be unlocked to recover from previously reported preparation errors
I'm trying to run(debug) an Xcode watch app project on my watch. My phone is connected to my computer via USB cable, my watch is paired to my phone. When I open Xcode and then open "Devices and simulators", I can see my phone properly connected. But these errors show up for my watch........ Apple Watch may need to be unlocked to recover from previously reported preparation errors Ensure the device is unlocked and associated with the same local area network as this Mac. A connection to this device could not be established. Timed out while attempting to establish tunnel using negotiated network parameters. I have booted computer, phone and watch. I have turned wifi off and on, on all 3 devices. I have turned developer mode on the watch off and then back on again. Anyone have any ideas how to fix this?
4
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278
Oct ’25
Invalid parameter not satisfying: parentEnvironment != nil
Since the beta releases of iPadOS 26 we have been having some crashes about Invalid parameter not satisfying: parentEnvironment != nil We got to contact a couple of users and we found out that the crash appears when entering a screen in a UINavigationController with the iPad device connected to a Magic Keyboard. If the device is not connected to the keyboard then nothing happens and everything works ok. From our end we haven't managed to reproduce the crash so I am pasting part of the stacktrace if it can be of any help. 3 UIKitCore 0x19dfd2e14 -[_UIFocusContainerGuideFallbackItemsContainer initWithParentEnvironment:childItems:] + 224 (_UIFocusContainerGuideFallbackItemsContainer.m:23) 4 UIKitCore 0x19dae3108 -[_UIFocusContainerGuideImpl _searchForFocusRegionsInContext:] + 368 (_UIFocusGuideImpl.m:246) 5 UIKitCore 0x19db28498 -[_UIFocusMapSnapshot addRegionsInContainer:] + 2720 (_UIFocusMapSnapshot.m:531) 6 UIKitCore 0x19db28900 -[_UIFocusMapSnapshot addRegionsInContainers:] + 160 (_UIFocusMapSnapshot.m:545) 7 UIKitCore 0x19d1313dc _UIFocusRegionSearchContextSearchForFocusRegionsInEnvironment + 632 (_UIFocusRegion.m:143) 8 UIKitCore 0x19db1d244 -[_UIFocusRegionContainerProxy _searchForFocusRegionsInContext:] + 140 (_UIFocusRegionContainerProxy.m:184) 9 UIKitCore 0x19db28498 -[_UIFocusMapSnapshot addRegionsInContainer:] + 2720 (_UIFocusMapSnapshot.m:531) 10 UIKitCore 0x19d1320fc _UIFocusItemContainerAddChildItemsInContextWithOptions + 596 (UIFocusItemContainer.m:183) 11 UIKitCore 0x19d131b98 _UIFocusRegionSearchContextAddChildItemsInEnvironmentContainer + 648 (_UIFocusRegion.m:108) 12 UIKitCore 0x19d131398 _UIFocusRegionSearchContextSearchForFocusRegionsInEnvironment + 564 (_UIFocusRegion.m:140) 13 UIKitCore 0x19db1d244 -[_UIFocusRegionContainerProxy _searchForFocusRegionsInContext:] + 140 (_UIFocusRegionContainerProxy.m:184) 14 UIKitCore 0x19db28498 -[_UIFocusMapSnapshot addRegionsInContainer:] + 2720 (_UIFocusMapSnapshot.m:531) 15 UIKitCore 0x19d1320fc _UIFocusItemContainerAddChildItemsInContextWithOptions + 596 (UIFocusItemContainer.m:183) 16 UIKitCore 0x19d131b98 _UIFocusRegionSearchContextAddChildItemsInEnvironmentContainer + 648 (_UIFocusRegion.m:108) 17 UIKitCore 0x19d131398 _UIFocusRegionSearchContextSearchForFocusRegionsInEnvironment + 564 (_UIFocusRegion.m:140) 18 UIKitCore 0x19db1d244 -[_UIFocusRegionContainerProxy _searchForFocusRegionsInContext:] + 140 (_UIFocusRegionContainerProxy.m:184) 19 UIKitCore 0x19db28498 -[_UIFocusMapSnapshot addRegionsInContainer:] + 2720 (_UIFocusMapSnapshot.m:531) 20 UIKitCore 0x19d1320fc _UIFocusItemContainerAddChildItemsInContextWithOptions + 596 (UIFocusItemContainer.m:183) 21 UIKitCore 0x19d131b98 _UIFocusRegionSearchContextAddChildItemsInEnvironmentContainer + 648 (_UIFocusRegion.m:108) 22 UIKitCore 0x19d131398 _UIFocusRegionSearchContextSearchForFocusRegionsInEnvironment + 564 (_UIFocusRegion.m:140) 23 UIKitCore 0x19db1d244 -[_UIFocusRegionContainerProxy _searchForFocusRegionsInContext:] + 140 (_UIFocusRegionContainerProxy.m:184) 24 UIKitCore 0x19db28498 -[_UIFocusMapSnapshot addRegionsInContainer:] + 2720 (_UIFocusMapSnapshot.m:531) 25 UIKitCore 0x19d1320fc _UIFocusItemContainerAddChildItemsInContextWithOptions + 596 (UIFocusItemContainer.m:183) 26 UIKitCore 0x19d131b98 _UIFocusRegionSearchContextAddChildItemsInEnvironmentContainer + 648 (_UIFocusRegion.m:108) 27 UIKitCore 0x19d131398 _UIFocusRegionSearchContextSearchForFocusRegionsInEnvironment + 564 (_UIFocusRegion.m:140) 28 UIKitCore 0x19db1d244 -[_UIFocusRegionContainerProxy _searchForFocusRegionsInContext:] + 140 (_UIFocusRegionContainerProxy.m:184) 29 UIKitCore 0x19db28498 -[_UIFocusMapSnapshot addRegionsInContainer:] + 2720 (_UIFocusMapSnapshot.m:531) 30 UIKitCore 0x19d1320fc _UIFocusItemContainerAddChildItemsInContextWithOptions + 596 (UIFocusItemContainer.m:183) 31 UIKitCore 0x19d131b98 _UIFocusRegionSearchContextAddChildItemsInEnvironmentContainer + 648 (_UIFocusRegion.m:108) 32 UIKitCore 0x19d131398 _UIFocusRegionSearchContextSearchForFocusRegionsInEnvironment + 564 (_UIFocusRegion.m:140) 33 UIKitCore 0x19db1d244 -[_UIFocusRegionContainerProxy _searchForFocusRegionsInContext:] + 140 (_UIFocusRegionContainerProxy.m:184) 34 UIKitCore 0x19db28498 -[_UIFocusMapSnapshot addRegionsInContainer:] + 2720 (_UIFocusMapSnapshot.m:531) 35 UIKitCore 0x19d1320fc _UIFocusItemContainerAddChildItemsInContextWithOptions + 596 (UIFocusItemContainer.m:183) 36 UIKitCore 0x19d131b98 _UIFocusRegionSearchContextAddChildItemsInEnvironmentContainer + 648 (_UIFocusRegion.m:108) 37 UIKitCore 0x19d131398 _UIFocusRegionSearchContextSearchForFocusRegionsInEnvironment + 564 (_UIFocusRegion.m:140) 38 UIKitCore 0x19db1d244 -[_UIFocusRegionContainerProxy _searchForFocusRegionsInContext:] + 140 (_UIFocusRegionContainerProxy.m:184) 39 UIKitCore 0x19db28498 -[_UIFocusMapSnapshot addRegionsInContainer:] + 2720 (_UIFocusMapSnapshot.m:531) 40 UIKitCore 0x19d132e08 -[_UIFocusMapSnapshot _capture] + 424 (_UIFocusMapSnapshot.m:403) 41 UIKitCore 0x19db2675c -[_UIFocusMapSnapshot _initWithSnapshotter:mapArea:searchArea:] + 476 (_UIFocusMapSnapshot.m:171) 42 UIKitCore 0x19d130dcc -[_UIFocusMapSnapshotter captureSnapshot] + 192 (_UIFocusMapSnapshotter.m:137) 43 UIKitCore 0x19db2045c -[_UIFocusMap _inferredDefaultFocusItemInEnvironment:] + 136 (_UIFocusMap.m:168) 44 UIKitCore 0x19daffd2c -[_UIFocusEnvironmentPreferenceEnumerationContext _inferPreferencesForEnvironment:] + 140 (_UIFocusEnvironmentPreferenceEnumerator.m:313) 45 UIKitCore 0x19d127ab4 -[_UIFocusEnvironmentPreferenceEnumerationContext _resolvePreferredFocusEnvironments] + 104 (_UIFocusEnvironmentPreferenceEnumerator.m:250) 46 UIKitCore 0x19d127394 -[_UIFocusEnvironmentPreferenceEnumerationContext preferredEnvironments] + 36 (_UIFocusEnvironmentPreferenceEnumerator.m:184) 47 UIKitCore 0x19d126e94 _enumeratePreferredFocusEnvironments + 400 (_UIFocusEnvironmentPreferenceEnumerator.m:503)
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2
126
Oct ’25
Avoid IPv6 communication when debugging with real device
We are experiencing troubles in our organization when we want to debug iOS applications on physical iPhones and iPads. Our iPhones (iPhone 16e, iOS 18.5) are not recognized by Xcode 16.4, but in the Finder they show up fine using the USB cable. We are aware, that the communication is different and there is an ad-hoc network that gets created to exchange the device profile. Together with our IT department responsible for our security infrastructure we narrowed it down to the following reason: As we are blocking all IPv6 traffic for local networking, the iPhone cannot communicate with Xcode to make the first connection and load the device profile. As they are not planning on changing this behavior, I am reaching out to you, if there is a way to force this first handshake between Xcode and iOS device to use IPv4? Or is there any other way to enable debugging for these devices? Any ideas would be very helpful.
3
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293
Oct ’25
iOS App Crashes after install but not when running from Xcode
I have an odd issue I'm trying to troubleshoot. I have an app that is deployed to our enterprise and works on almost all of our devices. Lately, I have devices (very small number) where the app installs from our MDM and it crashes upon launch, it does not get past the launch screen. If I remove and reinstall the app from the MDM it still crashes. I decided to put the devices in developer mode and if I run the App from Xcode on the device it works fine. If I stop it and run it right from the device it also works. If I do a final build of the app and install it using "Devices and Simulators", the app crashes upon launch. Using "Devices and Simulators" I check for crash log for the app and no file. I am stumped as to whats going on.
7
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178
Oct ’25
Unable to test my apps, crashing with provisioning profile validation
Since around September (iOS 26 release), i'm unable to test my app normally. It says "internet connection is required to verify [my certificate id]", or just crashing. All terms and conditions accepted, everything is valid, certificates are OK. Reinstallation via xcode does not help. Removal of provisioning profile, generating new does not help. Revoking of certificate and generating new does for around week, then it happens again, but do i need to do it every week now? In logs i see the following: default amfid validation failed because of missing trust and/or authorization (0xe8008026) error amfid not valid: 0xe8008026: The provisioning profile requires online authorization. error amfid Unexpected MISError (0xe8008026): The provisioning profile requires online authorization. default +0300 amfid /private/var/containers/Bundle/Application/5B8E560E-75B2-46EF-8606-02072D99E9CF//Frameworks/oss.dylib not valid: Error Domain=AppleMobileFileIntegrityError Code=-400 "An unknown error was encountered" UserInfo={NSURL=file:///private/var/containers/Bundle/Application/5B8E560E-75B2-46EF-8606-02072D99E9CF//Frameworks/oss.dylib, NSLocalizedDescription=An unknown error was encountered} default kernel AMFI: code signature validation failed. It looks like apple validation servers are not working, or is it iOS bug? All provisioning profiles are showing like "valid" in apple developer center. My network is not behind a proxy, connection is direct. If use EXACTLY the same app, signed with the same provisioning, same signature, on another test device, it works! When i reset current device to default settings and installing the EXACTLY same app after it, it works as well. Looking for a help from apple developer support
0
1
123
Oct ’25
CarPlay app not receiving data updates when iPhone screen is locked
We are building a CarPlay app and have run into an issue with data updates. When the app is running on the CarPlay display and the iPhone screen is locked, no data updates are shown on the CarPlay screen. As soon as the phone is unlocked, the data updates appear instantly on the CarPlay display. Has anyone encountered this behavior before? Is there a specific setting, entitlement, or background mode we need to enable in order to ensure the CarPlay app continues to receive and display data while the iPhone is locked? Any guidance would be greatly appreciated.
3
2
232
Oct ’25
Fatal safeAreaInsets Error on Certain iOS/iPadOS 26 Devices
Fatal safeAreaInsets Error on Certain iOS/iPadOS 26 Devices On certain devices that have updated to iOS/iPadOS 26, the safeAreaInsets value is displayed incorrectly when rotating. On the iPhone SE3, the safeAreaInsets.top value is displayed inverted when rotating. It should return 20.0 when rotated vertically and 0.0 when rotated horizontally. Currently, the value is reversed. (0.0 when rotated horizontally and 20.0 when rotated vertically.) On iPad Pro devices, the safeAreaInsets.top value is always returned as 0.0 when the app is first launched. (This issue is believed to occur on all iPad devices, including the iPad Pro.) If the user subsequently rotates the iPad, the safeAreaInsets value is returned correctly. On the iPhone 17 with dynamic islands, the safeAreaInsets value is displayed correctly. My guess is that all devices running iOS/iPadOS 26 without dynamic islands will experience an issue where the safeAreaInsets value is displayed incorrectly. This issue occurs when building with Xcode 26. Apple, please issue an OS update as soon as possible. Or, if this is an Xcode issue, please update Xcode.
4
2
376
Oct ’25
printf %a/%A misrounding (C99 compliance violation) when guard digit is 8
Note This issue has already been reported via Feedback Assistant as FB20512074, but the status is Investigation Complete – Unable to Diagnose with Current Information. Since this bug does not produce a crash log and is therefore difficult to capture through Feedback, I am also posting it here on the Developer Forum to provide additional details and to open discussion. ⸻ Description When formatting floating-point numbers with %a or %A, macOS libc sometimes rounds incorrectly when the guard digit equals 8. This leads to non-conformance with C99’s round-to-nearest, ties-to-even rule. ⸻ Steps to Reproduce #include <stdio.h> int main(void) { // precision 0 printf("%.0a\n", 1.5); printf("%.0a\n", 1.53); printf("%.0a\n", 1.55); printf("%.0a\n", 1.56); // precision 1 printf("%.1a\n", 0x1.380p+0); printf("%.1a\n", 0x1.381p+0); printf("%.1a\n", 0x1.382p+0); printf("%.1a\n", 0x1.383p+0); return 0; } Expected Results (per C99/C11) %.0a with inputs (1.5, 1.53, 1.55, 1.56): 0x2p+0 0x2p+0 0x2p+0 0x2p+0 %.1a with inputs (0x1.380p+0, 0x1.381p+0, 0x1.382p+0, 0x1.383p+0): 0x1.4p+0 0x1.4p+0 0x1.4p+0 0x1.4p+0 Actual Results (macOS observed) %.0a with inputs (1.5, 1.53, 1.55, 1.56): 0x1p+0 0x2p+0 0x1p+0 0x2p+0 %.1a with inputs (0x1.380p+0, 0x1.381p+0, 0x1.382p+0, 0x1.383p+0): 0x1.3p+0 0x1.4p+0 0x1.3p+0 0x1.4p+0 This shows that values slightly above half are sometimes treated as ties and rounded down incorrectly. ⸻ Root Cause Analysis Inside Libc/gdtoa/FreeBSD/_hdtoa.c, rounding is decided in dorounding(): if ((s0[ndigits] > 8) || (s0[ndigits] == 8 && (s0[ndigits + 1] & 1))) adjust = roundup(s0, ndigits); This logic has two mistakes: Half detection Correct: When the guard nibble is 8, all lower discarded digits must be checked. Current: Only the LSB of the next nibble is checked (& 1). Consequence: Cases like ...8C... (e.g. 1.55 ≈ 0x1.8C…) are strictly greater than half, but are treated as exact halves and rounded down. Tie-to-even parity check Correct: For a true half (all lower digits zero), rounding should use the parity of the last kept digit. Current: The code incorrectly uses the parity of the next discarded nibble instead. Consequence: True ties are not rounded to even reliably. ⸻ Proposed Fix (behavioral) if (s0[ndigits] > 8) { adjust = roundup(...); // strictly > half } else if (s0[ndigits] == 8) { if (any_nonzero_tail(s0 + ndigits + 1)) { adjust = roundup(...); // > half } else { // exact tie: round-to-even if (s0[ndigits - 1] & 1) adjust = roundup(...); } } ⸻ Impact This bug is not limited to %.0a; it occurs for any precision when the guard nibble is 8. It causes exact halves to round incorrectly and greater-than-half values to be rounded down. The effect is alternating outputs (zigzag) instead of consistent monotonic rounding. This is a C99 compliance violation.
1
0
188
Oct ’25
"Build input file cannot be found" error occurs in Archive.
"Build input file cannot be found" error occurs in Archive. When running Archive to generate a build file, the build file generation fails with a "Build input file cannot be found: ..." error. When debugging, the build runs fine on the actual device without any errors. Comparing and modifying the Build Settings with other projects doesn't fix the issue. Deleting the Swift file and attempting to Archive results in a crash due to the missing file. Even after deleting and adding the Swift file, the same error persists when attempting to Archive. Even after deleting and re-adding the Swift file, the issue persists even after deleting all DerivedData file space on my Mac and restarting Xcode. Can you help me with this issue? It worked fine before the recent macOS update, and I successfully archived and published it to the App Store a few days ago. I believe this issue occurred after updating macOS to 26.0.1. My Xcode version is 26.0.1.
1
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102
Oct ’25
new font warnings spamming my logs
Hi, I recently upgraded my device OS to 26.0 and XCode is on Version 26.0.1 (17A400) My XCode log is getting spammed with these types of errors all of a sudden. And filtering is so limited (filter a single item at a time) I can't remove them. It says to file a bug, can you folks PLEASE fix this it is making debugging really hard with all its noise. Unable to update Font Descriptor's weight to Weight(value: 0.3): UICTFontDescriptor <0x110e40180> = { NSFontNameAttribute = "SF Pro Display"; NSFontSizeAttribute = 16; } - SwiftUICore/Logging.swift:84 - please file a bug report. and UICTFontDescriptor <0x1181062e0> = { NSFontNameAttribute = "Inter Display"; NSFontSizeAttribute = 28; } - SwiftUICore/Logging.swift:84 - please file a bug report.
1
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204
Sep ’25
Xcode 26 Debug Error Display Issue
I recently installed Xcode 26.0.1. (MacBook Pro 16, M2 Max, 64GB memory, macOS 26.0 (25A354)) Normally, when debugging, a red error appears in the left-hand Issues navigation, and you can click on it to access the location of the error. However, currently, when debugging, the red error does not appear in the "Issue Navigation" on the left-hand side of the Xcode screen. There is an error, but it isn't displayed. It does appear, but disappears after 1 second. (It disappears before I can click on it.) The error doesn't appear or disappears after 1 second, so I can't pinpoint the exact location. Please help me resolve this issue. Additionally, I deleted all Xcode development-related files inside my Mac and restarted my MacBook, but the symptom still persists.
3
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234
Sep ’25
iOS Safari Web Extension MV3 - How to debug service workers?
I'm developing a web extension for Safari on iOS using MV3. The extension is working fine in Chrome, but in Safari I experience some seemingly random issues. I would like to debug it, but here is my problem. I have my iPhone connected via cable to Mac, and it works fine with XCode, so I assume this part is OK. I open Safari or Safari Tech Preview (doesn't matter) on my Mac, developers options are enabled, and in the Develop menu, under my iPhone section, there are things I can debug. There is an entry "[Ext name] - Extension Service Worker" but when I click it, it's empty. Web inspector pops up, but there are no network requests, no logs, nothing. I know the extension is working, because I can stream log to my HTTP server, but I don't see them here at all. I can use console to trigger commands like chrome.storage.local.get(null, console.log) and it shows my local store, so why I don't see any logs? Also, the background script is not visible in the Sources tab, just one weird request: navigator.serviceWorker.register('safari-web-extension://E3449EA7-EC25-4696-8E6C-[ID HERE]/background.js'); </script> Any ideas what went wrong? The entire team of 4 people has the same issue and we can't move forward because of that. Also, the Develop => Service workers or any other menu section doesn't show my service worker. Logs for websites running on my phone are visible and in general web inspector for them works fine.
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Sep ’25