Demonstration of a terminating Push Notification Service Extension on iOS 11

This is a minimal sample project in Xcode 9 and iOS 11 that demonstrates the unintentional termination of a push notification service with the error code Program ended with exit code: 0 when in debug mode. This makes it impossible to debug service extensions when using iOS 11 devices.

Versions used:

• Xcode 9.0 (9A235)
• iPhone 6 with iOS 11 (15A372)

Steps to reproduce

1. Checkout the project

2. In the developer portal of Apple, setup an AppId with Push Notifications enabled in Capabilities, make sure to adjust the bundle id in the project accordingly.

3. Create the needed certificates for sending push notifications in the development configuration and export them from the keychain into a aps_development.pem file

4. Build the main project (scheme ServiceExtensionMinimalProject) on a real device

5. Build and run ServiceExtension scheme on a real device and select the previously built extension to run with.

6. Once the app is started, put it to background (keep it connected to the debugger)

7. Send a rich push notification to the correct device token (it's printed in the console). I use Houston to send a push notifications easily:

   apn push "160dc27b1f2cdc72cc5262114ae29a78d040c71b5c9363ee4169817affe322c1"  -c aps_development.pem  -p -P '{"aps": {"alert": "New Push Notification", "badge": 0, "sound": "", "mutable-content": 1, "category": "myCategory", "content-available": 1}}'

8. Once the push notification arrives, it does not contain the [modified] prefix, which indicates that the push notification service extension was not properly executed. This is also visible by the error message in the console Program ended with exit code: 0. Breakpoints in the push notification service extension do not work at all.

Notes

• If you run this project (ServiceExtension scheme) without the debugger attached, the service extension is not killed and the push notification message contains the [modified] prefix (thus, the service extension was able to run and modify the payload).
• If you run the same app on a device with iOS 10.3.3 (14G60), the push notification service extension is correctly executed, the payload modified and also breakpoints in the debugger are working fine.
• This does not seem to be a problem with memory pressure since the push notification service extension is not doing anything at all.