IOS 12 Crash on launch, exactly after splash screen
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Hi, after update of the IOS 12, some of our users start to receive crash on launch, can you suggest anything about it. Callstack is:
Any suggestions?
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Hi,
What version of Qt are you using ?
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I have the same issue.
Affects all Qt versions at least as far back as 5.9. It occurs when selected Accessibility options are enabled on an iPhone running iOS 12. Features such as "Speak Screen" or "Switch Controls" will cause the crash. I've not yet found a non-Qt application that is similarly affected.
It is easily reproducible by creating a new Qt (widgets) application and hitting "Run".
It seems that ALL UIViews will return int64 max (or -1) for accessibilityElementCount.
I've tried swizzling and overriding implementations to overcome the issue to no avail. You can workaround the issue by reimplementing QUIView's becomeFirstResponder to return NO. Unfortunately however, you will no longer be able to use text input widgets
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I'm using Qt5.9.4. You are right Andrew, when i enable Speak Screen, crash was 100% reproducible on all my IOS devices. I am not sure about widgets application, cause my application is QML. Cause on mobile we don't need window title, cause it is not visible at all, it was empty string for our application. After a lot of investigation, I put a title for our application and it stop crashing, doesn't matter Speak Screen is enabled or not. For me, this is very very strange, but for now this fix our issue...
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I'm using Qt5.9.4. You are right Andrew, when i enable Speak Screen, crash was 100% reproducible on all my IOS devices. I am not sure about widgets application, cause my application is QML. Cause on mobile we don't need window title, cause it is not visible at all, it was empty string for our application. After a lot of investigation, I put a title for our application and it stop crashing, doesn't matter Speak Screen is enabled or not. For me, this is very very strange, but for now this fix our issue...
@Dimitar.Negrevski you should open an Issue to get this fixed and also provide your workaround there
hmmm. just tried some accessibility options with a Qt 5.10.1 QtQuickControls2 app and have no crashes on iOS 12.
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@ekkescorner bug is reported: https://bugreports.qt.io/browse/QTBUG-70909
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@ekkescorner bug is reported: https://bugreports.qt.io/browse/QTBUG-70909
@Dimitar.Negrevski just tried to reproduce with my QtQuickControls2 App (Qt 5.10.1) on iOS 12, but got no crash.
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@Dimitar.Negrevski just tried to reproduce with my QtQuickControls2 App (Qt 5.10.1) on iOS 12, but got no crash.
@ekkescorner With Qt5.9.4 with qt examples it is not 100% reproducible on all devices. But we have one device on which it is 100% reproducible with all applications, but we still can't understand what exactly is causing all qt apps to crash on this iPhone 7(ios 12). I compare most of the device settings with other device on which it is not reproducible with examples, and everything looks same. In few days I will test it with Qt 5.10 or Qt 5.11 too, and I will write what's the result on this iPhone with this Qt versions.
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@ekkescorner With Qt5.9.4 with qt examples it is not 100% reproducible on all devices. But we have one device on which it is 100% reproducible with all applications, but we still can't understand what exactly is causing all qt apps to crash on this iPhone 7(ios 12). I compare most of the device settings with other device on which it is not reproducible with examples, and everything looks same. In few days I will test it with Qt 5.10 or Qt 5.11 too, and I will write what's the result on this iPhone with this Qt versions.
@Dimitar.Negrevski https://bugreports.qt.io/browse/QTBUG-70683 seems to be a similar issue
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@Dimitar.Negrevski https://bugreports.qt.io/browse/QTBUG-70683 seems to be a similar issue
@ekkescorner Yep, it looks similar, it will be interesting if they find another workaround.
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I have I think the same problem (Widget based application crashing for some users after upgrading to iOS 12)
From the bug reports it is not clear to me if there is a workaround?@maitai_vw For our QML application, adding a title to our QML Window fix the crash.
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@maitai_vw For our QML application, adding a title to our QML Window fix the crash.
@Dimitar.Negrevski Thanks for your reply
My app is widget based. Adding a title to mainwindow passed the crash, but that is not enough. Uses cannot access any menu anymore (i.e. when taping on an action it crashes). Investigation is underway but difficult since I do not have an iOS device compatible with iOS 12. -
@Dimitar.Negrevski Thanks for your reply
My app is widget based. Adding a title to mainwindow passed the crash, but that is not enough. Uses cannot access any menu anymore (i.e. when taping on an action it crashes). Investigation is underway but difficult since I do not have an iOS device compatible with iOS 12.@maitai_vw said in IOS 12 Crash on launch, exactly after splash screen:
... I do not have an iOS device compatible with iOS 12.
have you tried with Simulator ?
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@Dimitar.Negrevski Thanks for your reply
My app is widget based. Adding a title to mainwindow passed the crash, but that is not enough. Uses cannot access any menu anymore (i.e. when taping on an action it crashes). Investigation is underway but difficult since I do not have an iOS device compatible with iOS 12.@maitai_vw Are you sure that menu crash is related to IOS 12, cause with our QML App, we don't have any problems with Menu.
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Still searching on that one.
I have 2 users concerned, on iPhone 6S both. Many others do not have the problem
I do not have a 6S to test with, even worst no device iOS 12 compatible.
Only thing I can tell is that I get this crash report in XCode from appstoreUIAccessibility: _axuiElementForNotificationData
and nothing more.
Users swear they didn't set any accessibility stuff. Only common point is that they are both located in Swiss, lol.
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Still searching on that one.
I have 2 users concerned, on iPhone 6S both. Many others do not have the problem
I do not have a 6S to test with, even worst no device iOS 12 compatible.
Only thing I can tell is that I get this crash report in XCode from appstoreUIAccessibility: _axuiElementForNotificationData
and nothing more.
Users swear they didn't set any accessibility stuff. Only common point is that they are both located in Swiss, lol.
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Finally it appears that users were, well, lying. They did have some accessibility options on, namely "speak screen" and another one. Once they finally removed it's all OK
To summarize:
I had the crash you reported, and I added a title to mainwindow (my app is widget-based, not qml)
That fixed the crash. But still there is a crash later if user is calling a qaction (I guess it's trying to speak the qaction.).
Is there a setting in plist or something to override to avoid that? -
Yep, it seems that with IOS 12.1 everything is fine, without any workaround. How can I mark issue as resolved?
