If you need help investigating a crash, please include a crash report in your post. To smooth things along, follow these guidelines: For information on how to get a crash report, see Acquiring crash reports and diagnostic logs. Include the whole crash report as a text attachment (click the paperclip icon and then choose Add File). This avoids clogging up the timeline while also preserving the wealth of information in the crash report. If you’re not able to post your crash report as an attachment, see Can’t Post Crash Report as Attachment below. If you want to highlight a section of the report, include it in the main body of your post. Put the snippet in a code block so that it renders nicely. To create a code block, add a delimiter line containing triple backquotes before and after the block, or just click the Code Block button. If possible, post an Apple crash report. Third-party crash reporters are often missing critical information and have general reliability problems (for an explanation as to why, see Implementing Your Own Crash Reporter). Symbolicate your crash report before posting it. For information on how to do this, see Adding identifiable symbol names to a crash report. If you need to redact the crash report, do so consistently. Imagine you’re building the WaffleVarnish app whose bundle ID is com.example.wafflevarnish but you want to keep your new waffle varnishing technology secret. Replace WaffleVarnish with WwwwwwVvvvvvv and com.example.wafflevarnish with com.eeeeeee.wwwwwwvvvvvvv. This keeps the text in the crash report aligned while making it possible to distinguish the human-readible name of the app (WaffleVarnish) from the bundle ID (com.example.wafflevarnish). Finally, for information on how to use a crash report to debug your own problems, see Diagnosing issues using crash reports and device logs. Can’t Post Crash Report as Attachment Crash reports have two common extensions: .crash and .ips. If you have an .ips file, please post that [1]. DevForums lets you attach a .crash file but not an .ips file (r. 117468172). To work around this, change the extension to .txt. If DevForums complains that your crash report “contains sensitive language”, leave it out of your initial post and attach it to a reply. That often avoids this roadblock. If you still can’t post your crash report, upload it to a file sharing service and include the URL in your post. Post the URL in the clear, per tip 14 in Quinn’s Top Ten DevForums Tips. Getting a Crash Report from the Xcode Organiser The Xcode organiser shows crash reports from customers. If you’re investigating such a crash and want to post a crash report: Navigate to the crash in the Xcode organiser. Note If you can’t see the right crash, check the filter popups at the top. In the list of crashes, secondary click on your crash and choose Show in Finder. That reveals the Xcode crashpoint document (.xccrashpoint) in the Finder. Secondary click on that and choose Show Package Contents. In the resulting Finder window, find a crash report (.crash) that accurately represents the crash you’re investigating and attach that to your forums post. Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com" [1] Because it’s easy to go from an .ips file to a .crash file. I usually do this by choosing File > Quick Look in the Finder. For more info about these file formats, see this post. Revision History: 2025-08-29 Added the Getting a Crash Report from the Xcode Organiser section. 2024-11-21 Added a recommendation to post the .ips format if possible. 2024-05-21 Added some advice regarding the “contains sensitive language” message. 2023-10-25 Added the Can’t Post Crash Report as Attachment section. Made other minor editorial changes. 2021-08-26 First posted.

General: DevForums tags: Debugging, LLDB, Graphical Debugger Xcode > Debugging documentation Diagnosing memory, thread, and crash issues early documentation Diagnosing issues using crash reports and device logs documentation Choosing a Network Debugging Tool documentation Testing a release build documentation Isolating Code Signing Problems from Build Problems DevForums post What is an exception? DevForums post Language Exception from RCTFatal DevForums post Standard Memory Debugging Tools DevForums post Using a Sysdiagnose Log to Debug a Hard-to-Reproduce Problem DevForums post Posting a Crash Report DevForums post Creating a test project DevForums post Implementing Your Own Crash Reporter DevForums post Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com"

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>

dSYM size became thrice for builds generated via xcode 26 compared to xcode 16. These are all release builds.

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?

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)

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.

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.

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

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.

I have published a number of games that use SpriteKit for everything important. Since the release of macOS Tahoe, I've had a lot of end user reports saying that sound effects have stopped working in many (but not all) of my titles. I'm not doing anything unusual here – typical code is: sndGameOver = [SKAction playSoundFileNamed:@"Audio/GameOver.wav" waitForCompletion:YES]; Then at the appropriate time: [self runAction:sndGameOver]; Has anyone else encountered this? The code still works fine on previous operating systems, and appears to be fine on iOS too. Has something changed in macOS Tahoe? I'm at a bit of a loss. There's nothing obviously different between the titles that do work and the titles that don't. Suggestions welcomed! Thanks

Hi team, I'm looking for the RealityKit debugger in Xcode 26 beta 3. I'm running a RealityKit app on my iPad running iPadOS 26 b3, but the debugger option is not there in Xcode.

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.

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.

After updating to Xcode 26 RC on Tahoe 26 RC and iOS 26 RC (and now final version of both Tahoe and iOS). I'm still unable to debug on device. I've tried rebooting, resetting settings, cleaning trusted computers. I ran out of ideas, I was expecting that final versions would fix this but they didn't.

As of now, there is no Kernel Debug Kit (KDK) available for macOS 26.0 Developer Betas after the first build. Kernel Debug Kits are crucial for understanding panics and other bugs within custom Kernel Extensions. Without the KDK for the corresponding macOS version, tools like kmutil fail to recognize a KDK and certain functions are disabled. Additionally, as far as I am aware, a KDK for one build of macOS isn't able to be used on a differing build. Especially since this is a developer beta, where developers are updating their software to function with the latest versions of macOS, I'd expect a KDK to be available for more than one build.

"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.

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.

When utilizing Paperkit in its simplest form, PaperMarkupViewController does not show the option to add images. Furthermore, trying to add images directly to the PaperMarkup's insertNewImage() function does not display anything. It seems like image functionality is entirely broken on Xcode 26. This can be seen through the following example done by a fellow member here on the forums: https://gist.github.com/clarkezone/68eb3ee13b5607782ceb2e20cece4ab3

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.

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.

Hello, I'm trying to use Xcode's ARKit Session replay functionality. I have a capture I made using Reality Composer and when trying to use it with Xcode's replay functionality the installation and debugging process seems stalled forever. I've gotten it to work once so I know the capture file is functional but I have never gotten it to work a second time, even though I didn't change any settings. No amount of restarting Xcode, the Mac, or the iPhone seem to work. I have also tried cleaning build folders, reinstalling the app, and clearing DerivedData. I can confirm from the Xcode logs that the app installs correctly but the app never launches. If I unselect the checkbox for "ARKit Replay Data", the app launches and debugs nearly instantly. I have tried letting it "attach" for up to 10 minutes to no avail.