Empty viewhierarchy file sent during fatal crashes

[aellett]

Platform

iOS

Environment

Production

Installed

Manually

Version

8.56.2

Xcode Version

16.4

Did it work on previous versions?

No response

Steps to Reproduce

Start SDK with options.attachViewHierarchy = true and force a fatal crash.

Expected Result

It would be ideal if we could still attach the viewhierarchy to the error that happens. However, I understand that that might not be technically possible (and I see that this feature is noted as both "experimental" and "best effort" in the source documentation). But if we can't successfully attach a viewhierarchy file to the error event (or if the file is essentially empty json), I think that we shouldn't attach anything at all instead of just attaching the empty file. When I loaded the event in the console after the fatal crash, I had to spend time tracking down why it looks like I had a view hierarchy, but it was empty.

Alternatively/additionally, it might be helpful to add another comment to the source documentation that mentions that this probably won't work for fatal crashes.

Note: I also filed an issue for this on the getsentry/sentry repo here getsentry/sentry#101356 as I was thinking both the console and the sdk could handle things in a (separate?) way that made this clearer.

Actual Result

Here's the result in the console of forcing a fatal crash with this setting turned on:

Are you willing to submit a PR?

No response

[linear]

COCOA-789

[aellett]

I mentioned it in the other issue that I linked to, but just wanted to add here that if I do the same steps in the same place with a nonfatal issue that the viewhierarchy shows up exactly as expected.

[philipphofmann]

I can easily reproduce this problem with our sample app, both with a TestFlight build with 8.57.0 and on a simulator. The problem also exists with the TestFight build 2330 that uses 8.53.2.

It's worth noting that the screenshot still works for crashes. The crash handler tries to get the view hierarchy here

sentry-cocoa/Sources/SentryCrash/Recording/SentryCrashC.c

Lines 102 to 109 in c1254d8

	if (sentrycrashfu_makePath(crashAttachmentsPath)) {
	if (g_saveScreenShot) {
	g_saveScreenShot(crashAttachmentsPath);
	}
	if (g_saveViewHierarchy) {
	g_saveViewHierarchy(crashAttachmentsPath);
	}

We need to investigate since which Cocoa SDK version this is broken, which should then help us to find the root cause.