How to add debug symbols to build.gradle

Question

I have created android build of my Flutter application.

Then I created an internal testing release. It is showing a warning

This App Bundle contains native code, and you've not uploaded debug symbols. We recommend you upload a symbol file to make your crashes and ANRs easier to analyze and debug.

Basically what I had to do is add following to build.gradle file according to the link they show.

android.buildTypes.release.ndk.debugSymbolLevel = { SYMBOL_TABLE | FULL }

I assume it is android/app/build.gradle they are talking about.

Not sure exactly where in that file I have to add this line.

Can someone point out where to add this line?

Solution 1

To use the option ndk debugSymbolLevel as written in the docs you need an android gradle plugin 4.1 or later. At the time of writing the lastest 4.1 version is 4.1.2

You will need also to install ndk and cmake for android studio.

In your android build.gradle you need the to set android gradle plugin version 4.1.2:

buildscript {
    ...
    repositories {
        google()
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:4.1.2'
        ...
    }

Then in the android/app build.gradle add:

...
android {
    ...
    // you see the ndk version in the android studio sdk-manager
    // have a look also here: https://stackoverflow.com/a/65747847/9481613
    ndkVersion "21.3.6528147" 
    ...
    buildTypes {
        release {
            ...
            ndk {
                debugSymbolLevel 'SYMBOL_TABLE'
            }
        }   
    }
}

when you then run: flutter build appbundle it should finish after a while with an appbundle that is twice the size.

Solution 2

There's two places in the app/build.gradle where you can specify bundling of debugging symbols with your app. If you use android.defaultConfig.ndk.debugSymbolLevel it will apply it to all build types (i.e., both debug and release builds). On the other hand, if you use android.buildTypes.release.ndk.debugSymbolLevel it will apply only to your release build.

These options have to be added into your app/build.gradle file as you correctly guessed. When you see a build property that's in this dotted notation, it actually corresponds to nested blocks in the build.gradle, which would look a bit like this:

android {
    compileSdkVersion 28
    defaultConfig {
        applicationId 'com.example.foo'
        minSdkVersion 23
        targetSdkVersion 28
        versionCode 42
        versionName "4.0.2"
        ndk {
            debugSymbolLevel 'SYMBOL_TABLE'
        }
    }
    // Rest of the file
}

HTH

Solution 3

If none of solutions work, you can also create a Sample JNI Application from Android Studio's project templates. Build it and check whether it got built successfully and installed on a device.

I have inspected its app build.gradle file and compared my Flutter's build.gradle. So I added this to make it work:

defaultConfig {

    // append below:
    externalNativeBuild {
            cmake {
                cppFlags "-std=c++17"
            }
        }
}

Solution 4

Use Android Version 4.1 and above currently 4.1 RC 3 and 4.2 Canary 13 is available, and similarly use com.android.tools.build:gradle 4.1 and above, you can search for the suitable version from here

Then use this line in android -> defaultConfig in your app build.gradle file

    ndk { debugSymbolLevel 'FULL' }

View more solutions

Comments

[Pratik Butani]

Minimum gradle-6.6.1-all.zip in gradle-wrapper.properties required for latest gradle (4.2.0-alpha12') plugin

[user3508953]

gradle-6.5 is the minimum. Just change the plugin version: classpath 'com.android.tools.build:gradle:4.1.0' in the top level gradle file. This will prompt to fix gradle and will install 6.5. Keep in mind, this required android studio version 4.1 or higher.

[pierrea]

Amazing, thank you! Question: why choose 'SYMBOL_TABLE' over 'FULL' ?

[Adam]

Hi @pierrea, both attributes are described in the first link of the answer. Bascially its how much debug information you want to include: Note: There is a 300 MB limit for the native debug symbols file. If your debug symbols footprint is too large, use SYMBOL_TABLE instead of FULL to decrease the file size.

[JJD]

Do you know if this configuration option does also pick up unstripped debug symbols packaged in a library *.aar which is downloaded as a Maven artifact?

[Web.11]

Where I can find a file to upload on playstore ?

[Davide Bicego]

Read here developer.android.com/studio/build/…

[kyu]

If the appbundle is twice the size, does the app on the play store also doubles the size?

[Adam]

Would make sense to me. You can also run flutter build appbundle --analyze-size to see what is inside. Typically you would add debug information to you build for beta testing but not in a production release.

[Zoran]

Native debug symbols are included in app bundle, but if you use apk they are located here: app/build/outputs/native-debug-symbols/variant-name/native-d‌​ebug-symbols.zip

[mLstudent33]

this answer shows how to use the menu to get the ndk version number: stackoverflow.com/a/65747847/9481613

[Adam]

Hi @mLstudent33, thanks for the input. I had that previously in the comment but just see I put a bash style comment before. I fixed that and added your link to show ndk version in android studio sdk-manager

[genericUser]

Is it meaningless to add symbol files to an obfuscating bundle? On one hand I want to difficult reverse engineer, on the other hand I want to be able to read my stackTrace (I'm using firebase crashalytics) @Alberto

[Alberto]

That's not a problem. The proguard mappings and unstripped libraries are never sent to users when they install your app so there's no reverse engineering possible. It is all securely stored in Play Console and used for the crash reporting features.

[Bugzilla]

Do you still need to pass the --obfuscate --split-debug-info flags for the ofuscation to take place?

[Adam]

Hi @Bugzilla, I think yes. For flutter 2.5.3 running the help flutter build appbundle -h shows: "In a release build, this flag removes identifiers and replaces them with randomized values for the purposes of source code obfuscation. This flag must always be combined with "--split-debug-info" option, the mapping between the values and the original identifiers is stored in the symbol map created in the specified directory. For an app built with this flag, the "flutter symbolize" command with the right program symbol file is required to obtain a human readable stack trace."

[vietstone]

Still does not work for me :D. Don't know why. And I still see Task :app:stripReleaseDebugSymbols in the output of flutter build appbundle -v

[Ton]

Do I have to add the line ndkVersion "21.3.6528147" somewhere? If so, where?

[Hamza Waleed]

To upload on store, mapping dSYM file can be found in android/app/build/outputs/mapping/release/mapping.txt