According to this page: https://developer.apple.com/documentation/xcode/interpreting-the-json-format-of-a-crash-report
the storeInfo element of a JSON crash log may contain a deviceIdentifierForVendor element, but quote "This field is only present for TestFlight builds of an app".
A user has just sent me a crash report which contains this key, but this isn't a testflight build.
The suspicion is of course that the app is "cracked" in some way, but having interacted with the user for some time I think this is unlikely. He has had various issues with the app, affecting multiple devices; I have been wondering if there is something wrong with his Apple account.
The docs also say that this "replaces the CrashReporter Key field", yet this crash report contains both.
So my question for other developers: if you have any .ips crash logs, obtained from non-testflight users of your apps, please could you grep them for deviceIdentifierForVendor and let me know what you find.
If any Apple people have any clues about how this could innocently end up in a crash report, please let me know. Maybe it's a documentation bug?