Crashlytics for mobile apps in Qt

SyntaX

Hey there :D

I wanted to add Crashlytics to my Qt Project (for now only for Android) but stumbled across some issues :/

Seems like, I am not the first one having troubles,
but I didn't manage to find a solution that works :/

@RonaldoD I found your post, back from 2015. I know, that's a little outdated, but I was wondering, if you have some useful hints? Sadly, the website I not available anymore :(
Re: Integrate Qt Android Application with Crashlytics Tools

What I managed so far, was the integration of the Firebase Crashlytics SDK from google (not the "old" Fabric SDK)
for the native android java side, essential code below:

build.gradle

...
apply plugin: 'com.google.firebase.crashlytics'

dependencies {
    ...
    // Add the Firebase SDK for Crashlytics.
    //implementation 'com.crashlytics.sdk.android:crashlytics:2.10.1' // old fabric
    implementation 'com.google.firebase:firebase-crashlytics:17.0.0-beta03'

    // Add the Crashlytics NDK dependency.
    //implementation 'com.google.firebase:firebase-crashlytics-ndk:17.0.0-beta03'

which seems to work for exceptions and logging on the android side

mFirebaseCrashlytics.log("crashing!"); // log error

try {
    throw new RuntimeException("Test Crash");
} catch (Exception exc) {
    mFirebaseCrashlytics.recordException(exc); // capture Android stack trace
}

But if the App really crashes, it seems that there is no stack trace available in my Crashlytics reports.
Application output from Qt Creator is something like this

#30 pc 0023c840  /data/app/com.test.app-RkCEhhQMFtPWdUreXh90mw==/lib/x86/libQt5Core_x86.so (void QJNIObjectPrivate::callStaticMethodV<void>(_jclass*, char const*, char const*, char*)+72)
#31 pc 0023c8be  /data/app/com.test.app-RkCEhhQMFtPWdUreXh90mw==/lib/x86/libQt5Core_x86.so (void QJNIObjectPrivate::callStaticMethod<void>(_jclass*, char const*, char const*, ...)+58)
#32 pc 00023b50  /data/app/com.test.app-RkCEhhQMFtPWdUreXh90mw==/lib/x86/libplugins_platforms_qtforandroid_x86.so (???)

No pending exception expected: java.lang.RuntimeException: forced runtime exception
at void com.test.app.MyApp.testCrash() (myapp.java:85)

I am not really familiar with the Qt / depending mobile platform build systems,
but I assume I need to add the Crashlytics NDK to be able to capture the cpp/Qt stack trace?

But as soon, as I am adding :firebase-crashlytics-ndk:17.0.0-beta03 in the Gradle dependencies, my app crashes at startup:

I System.out: java: 15:26:50.GMT+02:00 > Android onCreate() hit in myActivity.java
W System  : ClassLoader referenced unknown path:
W System.err: java.lang.ClassNotFoundException: Didn't find class "org.qtproject.qt5.android.QtActivityDelegate" on path: DexPathList[[],nativeLibraryDirectories=[/system/lib, /system/product/lib]]
W System.err: 	at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:196)
W System.err: 	at java.lang.ClassLoader.loadClass(ClassLoader.java:379)
...
W System.err: 	at com.test.app.myActivity.onCreate(:61)

Following the guidelines from https://firebase.google.com/docs/crashlytics/ndk-reports-new-sdk I found that I need to

Run the following NDK-specific Gradle tasks:
./gradlew app:assembleBUILD_VARIANT
./gradlew app:uploadCrashlyticsSymbolFileBUILD_VARIANT

But I do not know, where / when to put these?

Also I don't really understand

Step 3 (optional): Upload symbols for external dependencies

What are "stripped libraries", how do I know which I need and where to find them?

Is there anyone with more experience, who can help me with this topic? :D
Any help is appreciated!

best Regards
SyntaX

SyntaX

ok, still don't know what exactly are unstripped / stripped libs are,
but I managed to get basic NDK reports running :D

the mentioned gradlew app:uploadCrashlyticsSymbol goes into the build.gradle file within the android tag:

afterEvaluate {
    assembleRelease.finalizedBy(uploadCrashlyticsSymbolFileRelease)
}

other settings can be taken from the official sdk documentation found here
https://firebase.google.com/docs/crashlytics/ndk-reports-new-sdk

SyntaX

I managed to achieve one step further to my goal :D

The 'libs' folder is generated during compilation, which contains the depending .so files,
which I was able to include with relative paths, from the build directory:

buildTypes {
        //debug
        release {
            // When minifyEnabled is set to true, Crashlytics automatically
            // uploads mapping files because the plugin detects that obfuscation
            // is enabled. mappingFileUploadEnabled defaults to true if
            // minifyEnabled is true.
            minifyEnabled true
            firebaseCrashlytics {
                //mappingFileUploadEnabled true

                // Enable processing and uploading of native symbols to Crashlytics
                // servers. By default, this is disabled to improve build speeds.
                // This flag must be enabled to see properly-symbolicated native
                // stack traces in the Crashlytics dashboard.
                nativeSymbolUploadEnabled true
                strippedNativeLibsDir '/libs'
                unstrippedNativeLibsDir '/libs'
            }
        }
    }

Although the full compilation now takes about 28 minutes on my machine, at least I am able to compile and deploy the application on my test devices (Emulator and Nexus 10 :D)

But if I open the application on my device, it immediately crashes xD

D/libcrashlytics(19474): Initializing native crash handling successful.
I/FirebaseCrashlytics(19474): Crashlytics NDK initialization successful
...
W/System.err(19474): java.lang.ClassNotFoundException: Didn't find class "org.qtproject.qt5.android.QtActivityDelegate" on path: DexPathList[[],nativeLibraryDirectories=[/vendor/lib, /system/lib]]
W/System.err(19474): 	at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
W/System.err(19474): 	at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
W/System.err(19474): 	at java.lang.ClassLoader.loadClass(ClassLoader.java:469)
...