Xcode 26.1 RC issue

Developer Tools & Services Xcode
jhowlin OP
Created Oct ’25
Replies 30
Boosts 30
Views 4.6k
Participants 26

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

Answered by jhowlin in 865862022

Yep. 26.1.1 fixes the issue. Thanks Xcode folks and everyone else here.

Replies  30
Boosts  30
Views  4.6k
Participants  26
mkdev OP
Nov ’25

Is this still happening in 26.1.1? The release notes don't mention this issue.
shreddit OP
Nov ’25

Looking good so far, ReportCrash is no longer tanking the cpu while a preview is open.
volmag OP
Nov ’25

I can confirm that 26.1.1 fixes it
DDP OP
Nov ’25

Updating the iOS 26.1 simulator from 23B80 to 23B86 looks good. The simulator shows wallpaper. So far ReportCrash doesn't have high CPU usage with simulator or canvas previews.
jhowlin OP
Nov ’25
Recommended

Yep. 26.1.1 fixes the issue. Thanks Xcode folks and everyone else here.

Xcode 26.1 RC issue
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