I created a sample Mac OS app with Notification Service Extension. The Extension is triggered when the push notification arrives and crashes while loading.
default 17:05:09.036408+0530 NotificationExtensionTest Hello, I’m launching as euid = 501, uid = 501, (persona not available)
error 17:05:09.043664+0530 NotificationExtensionTest Bootstrapping; external subsystem UIKit_PKSubsystem refused setup
default 17:05:09.043723+0530 NotificationExtensionTest Bootstrapping; Bootstrap complete. Ready for handshake from host.
default 17:05:09.044303+0530 NotificationExtensionTest [u 3F92D0CB-9A8F-4A8B-83C4-00F78A68C24C] [(null)((null))] Prepare received as euid = 501, uid = 501, (persona not available)
default 17:05:09.044646+0530 NotificationExtensionTest [u CCC8F807-11C3-4FB0-94DD-408AF5B202FA] [()] Set sole personality.
default 17:05:09.045083+0530 usernoted [u 3F92D0CB-9A8F-4A8B-83C4-00F78A68C24C:m (null)] [()] Begin using sent as euid = 501, uid = 501, (persona not available)
default 17:05:09.045185+0530 NotificationExtensionTest [u CCC8F807-11C3-4FB0-94DD-408AF5B202FA] [()] Begin using received as euid = 501, uid = 501, (persona not available)
default 17:05:09.045453+0530 usernoted [u 3F92D0CB-9A8F-4A8B-83C4-00F78A68C24C:m (null)] [()] plugin loaded and ready for host
error 17:05:11.010545+0530 usernoted Extension will be killed due to sluggish startup
error 17:05:11.010710+0530 usernoted [u 3F92D0CB-9A8F-4A8B-83C4-00F78A68C24C:m (null)] [()] Connection to plugin interrupted while in use.
default 17:05:11.010802+0530 usernoted [u 3F92D0CB-9A8F-4A8B-83C4-00F78A68C24C:m (null)] [()] terminating
error 17:05:11.011120+0530 usernoted [u 3F92D0CB-9A8F-4A8B-83C4-00F78A68C24C:m (null)] [()] Connection to plugin invalidated while in use.
error 17:05:14.049864+0530 NotificationExtensionTest WARNING: Did not receive handshake message from the host after waiting ~2 seconds. THIS MAY BE A SPURIOUS LAUNCH OF THE PLUGIN due to a message to an XPC endpoint other than the main service endpoint, or the CPU is highly contended and this extension or its host is not getting enough CPU time