I have a group of XCUItest suites that were designed to run in parallel on simulators. They run fine in xcode 16.2, but when I try to run them in Xcode 26 they run fine the first time, but on the second time I get an error that the simulator cannot be found: "No matching device (62621AD4-C8D6-4A1B-B511-79236113FD94) ". This UDID seems to be from one of the clones that were spawned on the previous test run. No matching device (62621AD4-C8D6-4A1B-B511-79236113FD94) in set at /Users/myUser/Library/Developer/XCTestDevices Domain: com.apple.CoreSimulator.SimError Code: 404 User Info: { DVTErrorCreationDateKey = "2026-02-26 22:52:53 +0000"; IDERunOperationFailingWorker = "_IDEInstalliPhoneSimulatorWorker"; }
If I clean all simulators and try to run again without closing Xcode, it keeps trying to access the clone that no longer exists. If I close an reopen xcode after removing all simulators ~/Library/Developer/XCTestDevices, xcode keeps trying the wrong device and I get the following error: Failed to clone device named 'iPhone 17 Pro'. (Underlying Error: The operation couldn’t be completed. Device was allocated but was stuck in creation state. Check CoreSimulator.log for more information.) This is what I get from CoreSimulator log: Feb 26 17:24:34 Mac-GD6GX5XH CoreSimulatorService[99200] <Warning>: Device 3C7BE1BE-416E-480A-BDA6-ADE8F0ADF818 encountered in creation state at launch. The device will be re-created. Feb 26 17:24:34 Mac-GD6GX5XH CoreSimulatorService[99200] <Error>: Failed to clone the device data path from /Users/MyUser/Library/Developer/CoreSimulator/Devices/7A5377DC-3ED9-4C8B-96EB-8DF7BEF4AE8B/data to /Users/MyUser/Library/Developer/XCTestDevices/3C7BE1BE-416E-480A-BDA6-ADE8F0ADF818/data, error = Error Domain=NSCocoaErrorDomain Code=260 "The file “data” couldn’t be opened because there is no such file." UserInfo={NSFilePath=/Users/MyUser/Library/Developer/CoreSimulator/Devices/7A5377DC-3ED9-4C8B-96EB-8DF7BEF4AE8B/data, NSURL=file:///Users/MyUser/Library/Developer/CoreSimulator/Devices/7A5377DC-3ED9-4C8B-96EB-8DF7BEF4AE8B/data, NSUnderlyingError=0x600000d04120 {Error Domain=NSPOSIXErrorDomain Code=2 "No such file or directory"}} Feb 26 17:24:34 Mac-GD6GX5XH CoreSimulatorService[99200] <Error>: Failed to re-create device that was encountered in the creation state (Clone 1 of iPhone 17 Pro (3C7BE1BE-416E-480A-BDA6-ADE8F0ADF818, iOS 26.2, Creating)): Error Domain=NSCocoaErrorDomain Code=260 "The file “data” couldn’t be opened because there is no such file." UserInfo={NSFilePath=/Users/MyUser/Library/Developer/CoreSimulator/Devices/7A5377DC-3ED9-4C8B-96EB-8DF7BEF4AE8B/data, NSURL=file:///Users/MyUser/Library/Developer/CoreSimulator/Devices/7A5377DC-3ED9-4C8B-96EB-8DF7BEF4AE8B/data, NSUnderlyingError=0x600000d04120 {Error Domain=NSPOSIXErrorDomain Code=2 "No such file or directory"}} Feb 26 17:24:34 Mac-GD6GX5XH CoreSimulatorService[99200] <Error>: New device is stuck in creation state, deleting: Clone 1 of iPhone 17 Pro (3C7BE1BE-416E-480A-BDA6-ADE8F0ADF818, iOS 26.2, Creating) Feb 26 17:24:34 Mac-GD6GX5XH CoreSimulatorService[99200] <Error>: Error Domain=NSPOSIXErrorDomain Code=22 "Invalid argument" UserInfo={NSLocalizedFailureReason=Device was allocated but was stuck in creation state. Check CoreSimulator.log for more information.} Feb 26 17:24:34 Mac-GD6GX5XH CoreSimulatorService[99200] <Error>: Error Domain=NSPOSIXErrorDomain Code=22 "Invalid argument" UserInfo={NSLocalizedFailureReason=Device was allocated but was stuck in creation state. Check CoreSimulator.log for more information.} Feb 26 17:24:34 Mac-GD6GX5XH com.apple.dt.Xcode[2744] <Error>: Error Domain=NSPOSIXErrorDomain Code=22 "Invalid argument" UserInfo={NSLocalizedFailureReason=Device was allocated but was stuck in creation state. Check CoreSimulator.log for more information.}