Sandbox app for the Mac App Store with Qt 5.8 and QtWebEngineProcess

[Wolosocu]

Attempting Qt 5.7.1 brought its own problem. Namely that on startup the application gives the error:

This application failed to start because it could not find or load the Qt platform plugin "cocoa"
in "".

Available platform plugins are: cocoa.

Reinstalling the application may fix this problem.
Abort trap: 6

I did a little research and tried a couple minor things but nothing worked.

Meanwhile my app was rejected because of an unused sandbox permission. So I've corrected that and resubmitted a new build still using Qt 5.6.2.

Really wish I had been able to get 5.8 to work or even 5.7.

[SGaist]

That strange, do you have a qt.conf file in your application bundle ?

[Wolosocu]

@SGaist Yes.

So, my app was rejected using Qt 5.6.2 because of the following:

Your app uses or references the following non-public API(s):

framework: '/System/Library/Frameworks/AppKit.framework/Versions/C/AppKit'
: NSAccessibilityUnregisterUniqueIdForUIElement
: _NSAppendToKillRing
: _NSDrawCarbonThemeBezel
: _NSDrawCarbonThemeListBox
: _NSInitializeKillRing
: _NSNewKillRingSequence
: _NSPrependToKillRing
: _NSSetKillRingToYankedState
: _NSYankFromKillRing

framework: '/System/Library/Frameworks/ApplicationServices.framework/Versions/A/ApplicationServices'
: CGSSetDenyWindowServerConnections
: CGSShutdownServerConnections
: CTFontCopyDefaultCascadeList

The use of non-public APIs is not permitted on the App Store as it can lead to a poor user experience should these APIs change.

Which looks like this is addressed by this: https://doc.qt.io/qt-5/qtwebengine-platform-notes.html#mac-app-store-compatibility

So I tried Qt 5.7 again and for whatever reason it didn't crash this time! However, it has the same exact problem I was seeing with Qt 5.8.

I have built and rebuilt and rebuilt QtWebEngine and yet I still cannot get it to work. Is there anyway to verify that my build of QtWebEngine is actually applying the use_appstore_compliant_code flag?

It seems like this has been a problem for a while: https://bugreports.qt.io/browse/QTBUG-41611

[SGaist]

The symbol problem is pretty surprising, are you sure you are using your build of the QtWebEngine module that is app store compliant ?

[Wolosocu]

@SGaist said in Sandbox app for the Mac App Store with Qt 5.8 and QtWebEngineProcess:

The symbol problem is pretty surprising, are you sure you are using your build of the QtWebEngine module that is app store compliant ?

I was using 5.6.2. Should I build 5.6.2 QtWebEngine with the use_appstore_compliant_code?

[Wolosocu]

@SGaist I'm back to trying Qt 5.8 again. I've gone so far as to manually copy over QtWebEngineCore.framework that is in my build folder and I'm getting the same results:

4/26/17 20:33:04.000 kernel[0]: Sandbox: QtWebEngineProce(86853) deny(1) mach-lookup org.chromium.Chromium.rohitfork.86852
4/26/17 20:33:04.019 QtWebEngineProcess[86853]: [0426/203304:ERROR:mach_port_broker.mm(43)] bootstrap_look_up: Permission denied (1100)
4/26/17 20:33:04.000 kernel[0]: Sandbox: QtWebEngineProce(86854) deny(1) mach-lookup org.chromium.Chromium.rohitfork.86852
4/26/17 20:33:04.020 QtWebEngineProcess[86854]: [0426/203304:ERROR:mach_port_broker.mm(43)] bootstrap_look_up: Permission denied (1100)
4/26/17 20:33:04.000 kernel[0]: Sandbox: QtWebEngineProce(86854) deny(1) forbidden-sandbox-reinit
4/26/17 20:33:04.000 kernel[0]: Sandbox: QtWebEngineProce(86853) deny(1) forbidden-sandbox-reinit

Again, is there anyway by inspecting the QtWebEngineCore.framework to make sure is being built with the app store compliant code?

[Wolosocu]

Just built QtWebEngine again on 5.8 and made sure to use the QtWebEngineCore.framework that just got built. No luck.

I see the use_appstore_compliant_code config item was added in Qt 5.7. Guess I'll try building that and see if I have any luck. Heck, I may even try 5.9 at this point just to see.

Seriously, has anyone successfully published an app that uses QtWebEngine to the MAS?

[Wolosocu]

Built 5.7 with use_appstore_compliant_code and am getting the same errors from my app:

4/27/17 07:10:53.000 kernel[0]: Sandbox: QtWebEngineProce(20764) deny(1) mach-lookup org.chromium.Chromium.rohitfork.20763
4/27/17 07:10:53.000 kernel[0]: Sandbox: QtWebEngineProce(20765) deny(1) mach-lookup org.chromium.Chromium.rohitfork.20763
4/27/17 07:10:53.627 QtWebEngineProcess[20764]: [0427/071053:ERROR:mach_broker_mac.mm(52)] bootstrap_look_up: Permission denied (1100)
4/27/17 07:10:53.627 QtWebEngineProcess[20765]: [0427/071053:ERROR:mach_broker_mac.mm(52)] bootstrap_look_up: Permission denied (1100)
4/27/17 07:10:53.000 kernel[0]: Sandbox: QtWebEngineProce(20764) deny(1) forbidden-sandbox-reinit

Are there any apps on the MAS that use Qt 5.x and QtWebEngine?

[SGaist]

That I don't know.

This thread might link to some clues that could help untangle your situation.

[Wolosocu]

@SGaist Thank you for trying to help. I discovered that link a few days ago while researching this problem. It did lead me to add the com.apple.security.application-groups entitlement to my app's entitlements file but the problem persists.

I am beginning to wonder if this is a problem with QtWebEngineProcess. I have posted this issue to the QtWebEngine mailing list but so far there has been no response.

I'm at a loss. :(

[Wolosocu]

As an alternative, is it possible to invoke C++ from a QtWebView? At this point I'm thinking of abandoning QtWebEngine altogether, though I would really like to avoid that.

[SGaist]

Do you mean from the QtWebView module ?

[Wolosocu]

@SGaist Yes. That does not use QtWebEngineProcess correct?

What I need is for a link in the HTML of the control to invoke some C++. I'm able to do this in QtWebEngine with QWebChannel. From what I've read, QtWebView doesn't really support that but maybe it's possible?

[SGaist]

No it doesn't use it.

AFAIK, QtWebView uses the platform native web views so it should be able to run with the QWebChanne module. Note that I haven't personally tested that combo but it's well worth a shot since it will likely make your application more lightweight.

[BeastBurst]

@Wolosocu said in Sandbox app for the Mac App Store with Qt 5.8 and QtWebEngineProcess:

QtWebEngineProce

@Wolosocu did you manage to overcome this issue? If so how ?