Xcode 26.1 RC issue

Question

Created 1w

Replies 17

Boosts 19

Views 1.1k

Participants 11

I'm seeing a lot of unexpected CPU usage when running the iOS 26.1 simulator. Looks like a "MercuryPosterExtension" is crashing over and over, which then causes the "ReportCrash" process to run, presumably to create the crash report.

Doesn't happen on device, nor on iOS 26.0 simulator. I suspect MercuryPoster is related to wallpaper. I also don't see any wallpaper background in my simulator.

Few lines from the stack trace:

Thread 0 Crashed:: Dispatch queue: com.apple.main-thread 0 libxpc.dylib 0x18011defc _xpc_api_misuse + 88

1 libxpc.dylib 0x18012e16c _xpc_shmem_create_with_prot.cold.1 + 24

2 libxpc.dylib 0x180113a70 _xpc_shmem_create_with_prot + 276

3 MTLSimDriver 0x23795ed48 -[MTLSimDevice newBufferWithLength:options:pointer:copyBytes:deallocator:] + 260

4 MercuryPosterExtension 0x10081d21c 0x100758000 + 807452

13 PosterKit 0x240d003d8 -[PRRenderer scene:willConnectToSession:options:] + 648

14 UIKitCore 0x1856bcf18 +[UIScene _sceneForFBSScene:create:withSession:connectionOptions:] + 956

Boost

Answer 1

weak OP

8h

I've just disabled ReportCrash:

launchctl unload -w /System/Library/LaunchAgents/com.apple.ReportCrash.plist 
sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.ReportCrash.Root.plist

To re-enable:

launchctl load -w /System/Library/LaunchAgents/com.apple.ReportCrash.plist 
sudo launchctl load -w /System/Library/LaunchDaemons/com.apple.ReportCrash.Root.plist

Overall it's a sad state of affairs tbh.

0

Answer 2

RickMaddy OP

3h

@Martin81 I get the ReportCrash issue running an iOS 26.1 simulator such as an iPhone 17 Pro. And it is showing a wallpaper. The only sims that don't show a wallpaper in my case are iPad simulators running iPadOS 26.1.

But here's what's really weird. I ran the Photos app in the iPhone 17 Pro simulator (which is showing the default wallpaper and causing high CPU). While viewing one of the stock simulator photos I chose "Use as Wallpaper". I went through the steps. Even though the chosen image is now appearing as a black wallpaper, it did fix the high CPU problem for that simulator.

Such a strange set of bugs.

1