It seems like, by default, the preview pane tries to align to 50% of the editor pane's width.
I prefer to shrink the preview pane to around ~30% of the screen so I have more space for code. This used to work fine—at least until I restarted Xcode. I never understood why the setting wouldn’t persist across sessions, but fine, that was a tradeoff I was willing to live with.
However, with Xcode 16.3, it seems like Xcode forgets the manually adjusted preview pane width as soon as I switch to a different file. This has definitely impacted my productivity, as I now find myself readjusting the pane size dozens of times in a single session.
Am I holding it wrong? Is anyone else experiencing this?
And while we’re at it—why not make this a persistent setting so everyone can tweak the width to their liking?
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Hi,
I’m facing a consistent simulator boot issue that appears to start after iOS 18.2 simulator runtimes and persists in 18.6, 26.1, and 26.2.
Observed behavior
iOS 18.2 simulator works fine
iOS 18.6 simulator does NOT boot
iOS 26.1 / 26.2 simulators do NOT boot
Tried everything reinstall/clear cache and all and event formatted the system
Unable to boot the Simulator
NSPOSIXErrorDomain Code: 4
Failure Reason: Interrupted system call
Failed to start launchd_sim: could not bind to session,
launchd_sim may have crashed or quit responding
macOS: Sequoia
Xcode: 26.1, 26.2
Machine: Apple Silicon
Unable to boot the Simulator. Domain: NSPOSIXErrorDomain Code: 4 Failure Reason: Interrupted system call User Info: { DVTErrorCreationDateKey = "2025-12-26 02:19:27 +0000"; IDERunOperationFailingWorker = "_IDEInstalliP.honeSimulatorWorker", Session = "com apple CoreSimulator.SimDevice CCDECA56-4A59-491B-A830-0F3928FCD957"; } Failed to start launchd_sim: could not bind to session, launchd_sim may have crashed or quit responding Domain: com.apple.SimLaunchHostService.RequestError Code: 4 Event Metadata: com.apple. dt. DERunOperationWorkerFinished : { "device_identifier" = "CCDECAE6-4A59-491B-A830-0E3928FCD957"; "device_model" = "iPhone18, 1"; "device_osBuild" = "26.1 (23B86)"; "device_osBuild_monotonic" = 2301008600; "device_os_variant" = 1; "device_platform" = "com apple.platform.iohonesimulator"; "device_platform_family" = 2; "device_reality" = 2; "device_thinningType" = "iPhone18,1"; "device_transport" = 4; "launchSession_schemeCommand" = Run; "launchSession_schemeCommand_enum" = 1; "launchSession_targetArch" = arm64; "launchSession_targetArch_enum" = 6; "operation_duration_ms" = 1183; "operation_errorCode" = 4; "operation_errorDomain" = NSPOSIXErrorDomain; "operation_errorWorker" = "_IDEInstalliPhoneSimulatorWorker"; "operation_error_reportable" = 1; "operation_name" = IDERunOperationWorkerGroup; "param_consoleMode" = 1; "param_debugger_attachToExtensions" = 0; "param_debugger_attachToXPC" = 1; "param_debugger_type" = 3; "param_destination_isProxy" = 0; "param_destination_platform" = "com apple platform
Please help on this as it got stuck.
Thanks
Hey all, I recently updated to Xcode 26.2 and I'm having the hardest time trying to download the corresponding iOS simulator. I installed Xcode from developer downloads and the app did not come loaded with an iOS simulator. When trying to download from Components in Settings, I only get the following message:
Download failed due to a bad URL. (Catalog download for com.apple.MobileAsset.iOSSimulatorRuntime)
Domain: com.apple.MobileAssetError.Download
Code: 49
User Info: {
checkConfiguration = 1;
}
I also tried downloading via Terminal but also get a download failed message. I am on the latest macOS and have over 600 GB of disk space available. In previous versions, I was able to download the iOS simulator directly from Developer Downloads, but anything after 26 is not there. Any suggestions?
I have a project which contains local packages. One of the packages has an explicit dependency on package A, but the main project also has the same dependency. Both of them are pinned to the exact version at all times.
Should I manage "shared" dependencies at the project level for local packages? This seems counter intuitive at first, but this question is originating from me fighting with a "Build service could not create build operation: unable to load transferred PIF: The workspace contains multiple references with the same GUID" error in Xcode 16 (all versions). It happens when I switch branches. Closing and reopening Xcode does resolve the issue, but it's a real flow killer.
The guide below doesn't mention dependency graph best practice.
https://developer.apple.com/documentation/xcode/organizing-your-code-with-local-packages
Thank in advance.
Hi everyone,
I’m experiencing a persistent issue when trying to download the iOS Simulator Runtime 26.1 on Xcode (version 26.1). The download always fails with the following error
Download failed due to a bad URL. (Catalog download for com.apple.MobileAsset.iOSSimulatorRuntime)
Domain: com.apple.MobileAssetError.Download
Code: 49
I’m located in Brazil, so I initially thought it might be region-related, but I’ve already tried several attempts to fix it, including:
Using VPNs for the US and Europe
Installing the Xcode 26.2 beta
Downgrading Xcode to earlier versions
Reinstalling the same version of Xcode
Restarting Xcode and my Mac
Switching networks
Clearing simulator support/device files
Unfortunately, nothing has resolved the issue.
Is anyone else facing this problem?
Does anyone know a workaround or a manual way to download/install the iOS 26.1 simulator runtime?
Thanks in advance!
I installed a custom font (Font awesome) into my app. I triple checked that I did everything right: the font files are included in the bundle (they appear in the "Copy Bundle Resources" build phase) and the names of the fonts appear in the Info.plist file under "Fonts provided by application".
In Interface builder, I select a Label, set the font to "Custom", then I click the Family list to select the font I want.
Once or twice, I was actually able to see the Font Awesome fonts in this list and select one. However, they no longer appear there when I create new labels in new views. I do not understand why. I've been limping along by copying a label from one of the views where it worked and pasting it into the new view, but this is tiresome.
I know the fonts are installed correctly because I can see them when I run the app.
Why are the fonts not showing up on the font list in interface builder?
Xcode is throwing an error when attempting to report test coverage after running unit tests.
Showing All Messages
Failed to merge raw profiles in directory /{my project dir}/DerivedData/{my project name}/Build/ProfileData/A98EC493-3AB4-4B1C-B7FC-BC5D77B23EE3 to destination /{my project dir}/DerivedData/{my project name}/Build/ProfileData/A98EC493-3AB4-4B1C-B7FC-BC5D77B23EE3/Coverage.profdata: Aggregation tool '/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/llvm-profdata' failed with exit code 1: warning: /{my project dir}/DerivedData/{my project name}/Build/ProfileData/A98EC493-3AB4-4B1C-B7FC-BC5D77B23EE3/997F01E3-3735-4897-AE00-31EBB0A9E8D3-57885.profraw: invalid instrumentation profile data (file header is corrupt)
error: no profile can be merged
Anyone else seeing this issue?
Using Xcode to build and deploy the app to my watch, this is what I get:
“Waiting to reconnect to Apple Watch. Previous preparation error: Transport error." And then “Connecting to Apple Watch. Xcode will continue when the operation completes.”
And these messages continue to switch between each other.
Sometimes the watch to connect and the application starts, but more often a scenario occurs with endless reconnection.
I'm using: MacOS 14.4.1 (MacBook Pro 2019; 1.4 GHz Quad-Core Intel Core i5), Xcode 15.3, Watch OS 10.2 (Apple Watch SE 1), iOS 17.1.1 (iPhone 15 Pro).
Methods I tried:
Connecting Macbook, iPhone and Watch to the same WIfi network;
Disabling Watch (and IPhone) from the "Devices and Simulators" menu and setting up Watch (and IPhone) from the beginning.
Any help?
Hi there,
I successfully created an AppIntent for our app, and when I had it in the same target as our main app it showed up fine in the shortcuts app.
Then I realized that many of the new System Control widgets introduced in iOS 18 (e.g. lockscreen, control center) live in the widget extension target, but they also need to reference that same AppIntent. So to fix this, I thought I'd migrate out the code into it's own SPM package that both the WidgetExtension and the Main App processes can reference. However, after doing that and rebuilding, the intent no longer shows up in the Shortcuts app. Furthermore, my AppShortcutsProvider class now has this error when trying to define the list of appShortcuts:
App Intent <name> should be in the same target as AppShortcutsProvider
Is this intended, and if so, how do we reference the same AppIntent across multiple targets?
After updating my Xcode to the latest, I am unable to download an installed app container from the Xcode Devices screen. This currently works with older versions of Xcode with the same app on the same iPad. This worked with older versions of Xcode on the same MacBook as well (including the Xcode 26 beta before updating to the official release yesterday)
The specified file could not be transferred.
Domain: com.apple.dt.CoreDeviceError
Code: 7000
User Info: {
DVTErrorCreationDateKey = "2025-09-18 20:31:01 +0000";
NSURL = "file:///Users/thomsk2/Desktop/com.test.polarisdev%202025-09-18%2015:30.53.744.xcappdata/AppData/Library/Caches/";
}
The specified file could not be transferred.
Domain: com.apple.dt.CoreDeviceError
Code: 7000
User Info: {
NSURL = "file:///Users/thomsk2/Desktop/com.test.polarisdev%202025-09-18%2015:30.53.744.xcappdata/AppData/Library/Caches/";
}
Failed to perform I/O operations.
Domain: com.apple.dt.remoteservices.error
Code: 11001
Failure Reason: Cannot open destination file /Users/thomsk2/Desktop/com.test.polarisdev 2025-09-18 15:30.53.744.xcappdata/AppData/Library/Caches/com.apple.dyld/standaloneapp.ios.dyld4: Permission denied
System Information
macOS Version 15.6.1 (Build 24G90)
Xcode 26.0 (24228) (Build 17A324)
Timestamp: 2025-09-18T15:31:01-05:00
Hi everyone,
I recently updated to Xcode 26.0 and noticed that the “Extract Subview” refactoring option seems to be missing.
Now, in Xcode 26, the only options I see under Editor -> Refactor -> are:
Extract to Selection File
Extract to Method
Extract to Variable
Extract All Occurrences
But there’s no Extract Subview as there was before.
Was Extract Subview intentionally removed in Xcode 26? Or is it hidden behind a new menu location or renamed?
Ever since updating to Xcode 16.3, auto-completing variable names in lldb does not work.
Is this a known bug? Is there a workaround to get it do auto-complete again?
When the Icon Composer file is imported into the project folder, and after building, there is a warning that says:
Failed to parse icontool JSON output.
Parts of the warnings show this:
Entity: line 1: parser error : Start tag expected, '<' not found
\211PNG
^
Entity: line 1: parser error : Start tag expected, '<' not found
\211PNG
^
Entity: line 1: parser error : Start tag expected, '<' not found
\211PNG
^
/* com.apple.actool.notices */
warning: Failed to parse icontool JSON output.
Underlying Errors:
Description: The data couldn’t be read because it isn’t in the correct format.
Failure Reason: The data is not in the correct format.
Debug Description: Garbage at end around line 6, column 0.
/* com.apple.actool.compilation-results */
I have created the icon with png files in each layer group in icon composer.
However the project is able to compile, and running shows the correct icon.
What is the issue with this?
I want to use a ci_script to change the CI_BUILD_NUMBER to a new value.
But in XCODE CLOUD there seems to be no programmatic way to change it?
Since the latest Xcode has become available users in our environment are seeing this error any time they try to launch a simulator (Primarily iOS devices, but others provided the same error) We have tested on 16.4 and 26.0.1 with various suggested fixes including uninstalling and reinstalling all of Xcode. Nothing has helped.
Hi,
Ever since I updated to macOS Tahoe and started using Xcode 26 daily, I've run into an issue where it gets stuck very frequently when launching and running my app in the simulator. It happens with the main app target as well as when running unit tests. If I restart Xcode and the simulator app, it works fine again for a while, but after some use, it goes back to the same situation. In Activity Monitor, Xcode ends up at 1000% CPU utilization for a minute or more, basically rendering the simulator and the debugger stuck. If I untick the "Debug Executable" option in the scheme editor, it works fine as well.
Anyone else run into the same situation, or are there any tips I can follow to fix this issue? It makes it really tedious to make changes and then be stalled for a minute or more to see the app run. I've restarted the Mac, erased the booted simulator as well. I'm on a MacBook Pro M4 Pro. Everything used to run fine before macOS Tahoe / Xcode 26 on my main device. In fact, I used to run macOS Tahoe / Xcode 26 beta versions on a separate partition without any problems.
Hi everyone,
I'm experiencing a persistent issue for months now where I'm unable to download the iOS 26 simulator Runtime. I've tried reinstalling Xcode and also Xcode Beta but same issue.
iOS 26 Simulator is also not on developers download page, so manual installation is impossible. And sadly I can't compile any code without having iOS 26 simulator installed.
Anyone able to get passed this?
Hardware: M1 Pro
OS: Tahoe 26.1
Heres the error
Download failed.
Domain: DVTDownloadableErrorDomain
Code: 41
User Info: {
DVTErrorCreationDateKey = "2026-01-07 11:35:35 +0000";
}
--
Download failed.
Domain: DVTDownloadableErrorDomain
Code: 41
--
Failed fetching catalog for assetType (com.apple.MobileAsset.iOSSimulatorRuntime), serverParameters ({
RequestedBuild = 23C54;
})
Domain: DVTDownloadsUtilitiesErrorDomain
Code: -1
--
Download failed due to not being able to connect to the host. (Catalog download for com.apple.MobileAsset.iOSSimulatorRuntime)
Domain: com.apple.MobileAssetError.Download
Code: 60
User Info: {
checkNetwork = 1;
}
--
System Information
macOS Version 26.1 (Build 25B78)
Xcode 26.2 (24553) (Build 17C52)
Timestamp: 2026-01-07T12:35:35+01:00
After updating from Xcode 16 to the new Xcode 26 beta 3, running my iOS app becomes slow to the point of unusable. It builds and installs fine, but when running with the console, it lags about 20-50x compared to building and running with Xcode 16. I wanted to try our Xcode 26 to preview my new app icon made in icon composer but now I don't think it's worth the hassle.
When running via simulator, the same performance issues. Anybody also struggling with slow on-device testing speed? I am on Sequoia 15.5.
Will RC be allowed to upload to App Store Connect?
I have tried a couple of times with 17A321 and I keep getting unsupported SDK or Xcode version.
Submitted feedback FB20178551
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