iOS 14 simulators crashing & rebooting

My iOS 14 simulators are constantly crashing/rebooting. Console shows a crash inside "NRPairedDeviceRegistry waitForPairingStorePathPairingID" whereas Xcode logs "XPC connection interrupted
Message from debugger: Terminated due to signal 9"

I have tried different simulators, deleted and reset existing one, re-installed the Xcode 12 beta 1 but it's still happening.

Any suggestions how to use the simulators?

Code Block
Crashed Thread: 0 Dispatch queue: com.apple.main-thread
Exception Type: EXC_CRASH (SIGKILL)
Exception Codes: 0x0000000000000000, 0x0000000000000000
Exception Note: EXC_CORPSE_NOTIFY
Termination Reason: Namespace LIBXPC, Code 0x4
Application Specific Information:
CoreSimulator 725.10 - Device: iPhone SE (2nd generation) (CAA00201-7B3F-4663-A855-F927586BDDD2) - Runtime: iOS 14.0 (18A5301v) - DeviceType: iPhone SE (2nd generation)
Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0 libsystem_kernel.dylib 0x00007fff5bb62e36 semaphore_wait_trap + 10
1 libdispatch.dylib 0x00007fff20104244 _dispatch_sema4_wait + 16
2 libdispatch.dylib 0x00007fff20104743 _dispatch_semaphore_wait_slow + 98
3 com.apple.private.NanoRegistry 0x00007fff52e2ff74 -[NRPairedDeviceRegistry waitForPairingStorePathPairingID:] + 175
4 com.apple.BulletinDistributorCompanion 0x00007fff47ede0b5 -[BLTSettingSyncServer init] + 260
5 com.apple.BulletinDistributorCompanion 0x00007fff47eb41f8 -[BLTSettingSyncInternal connect] + 29
6 com.apple.BulletinDistributorCompanion 0x00007fff47ecf1f4 -[BLTSettingSync initWithSectionConfiguration:queue:watchKitAppList:] + 134
7 com.apple.BulletinDistributorCompanion 0x00007fff47ec4e34 -[BLTBulletinDistributor init] + 660
8 com.apple.BulletinDistributorCompanion 0x00007fff47ec4b8b __43+[BLTBulletinDistributor sharedDistributor]_block_invoke + 16
9 libdispatch.dylib 0x00007fff20103dac _dispatch_client_callout + 8
10 libdispatch.dylib 0x00007fff20105001 _dispatch_once_callout + 20
11 com.apple.BulletinDistributorCompanion 0x00007fff47ec4b79 +[BLTBulletinDistributor sharedDistributor] + 46
12 bulletindistributord 0x000000010eb16388 0x10eb15000 + 5000
13 libdyld.dylib 0x00007fff20253941 start + 1


Answered by mbuchetics in 614707022
It looks like something is odd with device_set.plist. After I deleted the simulators, they are still in that plist as "Default Devices". After I removed them from the plist manually, the Xcode 12 simulator seems to be running fine again.
Please make sure to report this to the Sherlock team.
Anyone still experiencing this? I'm having similar issues with all beta versions. Tried everything suggested here and although I can get to a point where springboard isn't crashing repeatedly, I cannot get the app to fully launch. The closest I've gotten is it getting stuck at the loading screen forever.
Followed all the steps listed by mbuchetics and couldn't fully solve my issues. Springboard finally stopped crashing repeatedly, but I still couldn't fully load my app, it would hang on the loading screen. Followed all steps by mbuchetics again and also reset SMC. Finally everything is working again!
I've been experiencing a similar crash ever with Xcode 12 (and only 12) for months now. I included the output of the command and confirmed it includes numerous crash reports with various iOS 14 widgets. FB8737982 for reference.
I'm having the same problem, and it's driving me insane! The iOS 14 simulator is the worst offender, where multiple daemon processes seem to crash when the simulator finishes launch, and then again when the simulator is closed. I reverted to using an iOS 13.5 simulator and, although I do indeed experience less crashes, they are still occur and are similar (they're all SimulatorTrampoline related). It's almost as if there's some common code in the daemons that is not properly checking the existence of source/destination objects before trying to interact and so you get a crash. I've submitted my sysdiagnose and simdiagnose reports, as well as examples in FB8702058, so hopefully Apple is able to figure things out.

I can get the following sequence to reliably happen:
  1. With no simulator running, start Xcode 12 and load project.

  2. Use the iPhone SE 2nd Gen iOS 14 simulator and run the app.

  3. Once the simulator starts and completes its startup operations, you’ll get the following crashes: CalendarWidgetExtension, NewsTag, NewsToday2.

  4. The app will run. Depending on your app composition, you will probably get more simulator daemon crashes.

  5. Terminate the app.

  6. Terminate Xcode.

  7. Terminate the simulator. After a time (15 seconds?) you’ll get another crash: bulletindistributord. You may get other crashes when the simulator closes, but bulletindistributord is always the last.

The simulator instability began for me in the Xcode 11 line, where you'd routinely get maild crashes in the simulators. And this happened across multiple machines, each with different dev environments, so it's not just an isolate case for me. But Xcode 12 is now completely infected by the crashes.
Having the exact same problem in both of my machines. iMac 5k and MBP @ 2018:

I can get the following sequence to reliably happen:

Start Xcode 12 and create a new project (or load project)

Use any iOS 14 simulator and run the app.
Once the simulator starts and completes its startup operations, you’ll get the following crashes: CalendarWidgetExtension, NewsTag, NewsToday2.
The app will run. Depending on your app composition, you will probably get more simulator daemon crashes.
Terminate the simulator. After a time (15 seconds?) you’ll get another crash: bulletindistributord. You may get other crashes when the simulator closes, but bulletindistributord is always the last.


I removed Xcode and /Developer and preferences.
Tried with both versions (App Store) and from Dev. downloads. Same behavior.

Please, this is driving me crazy...
I have also some simulator processes constantly crashing - Xcode 12 with CalendarWidget et al, Xcode 11 some internal daemons - but I guess this is another issue than for the OP.

Wiping with xcrun simctl delete all and re-instantiating runtimes doesn't help.
@mcebrian: I'm so glad you confirmed the same behavior I'm experiencing. I've been searching across the internet ever since Xcode 11.5 started these crashes and couldn't find anything. I'm glad it's not just me.
@rshuston The only workaround I could find:

1) Create a new user in your mac.
2) The problem will be solved as the user library will be different. Which plist is causing the simulator to do this? Unknown for the moment.
Tanks to the people who mentioned Sherlock.
After quitting the Sherlock app it started working properly again!

I think the issue comes from the fact I was using a deprecated version.
In another related "Simulator crash reports" thread, user @TomE recommends using the CrashReporterPrefs utility to set the crash reporting mode to "Basic." The utility is in the "Utilities" folder of the "Additional Tools for Xcode" item in the Developer Downloads area. Mine was set to "Developer" and after I set it to "Basic" I stopped getting the pop-ups and I can run my automated tests again. While I really wish Apple would actually prioritize fixing their core bugs instead of relying on the lottery to groom their backlog, this at least lets me get back to being productive again.
iOS 14 simulators crashing & rebooting
 
 
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