Get Android NDK crash reports

If your Android app contains native libraries, you can enable full stack traces and detailed crash reports for your native code from Firebase Crashlytics with a few small updates to your app's build configuration. This guide describes how to configure crash reporting with the new Firebase Crashlytics SDK.

Before you begin

1. To get started, set up Crashlytics.

2. As a part of Step 2 (Add Firebase Crashlytics to your app), make sure your app is using the Crashlytics Gradle plugin v2.4.0+, which allows you to upload symbols using only your unstripped binaries to generate symbolicated crashes.

Step 1: Update your Gradle configuration

In your app-level build.gradle, declare the Crashlytics NDK runtime dependency:

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

dependencies {
  // ...

  // Import the BoM for the Firebase platform
  implementation platform('com.google.firebase:firebase-bom:28.0.1')

  // Declare the dependency for the Firebase Crashlytics NDK library.
  // If you previously declared the Firebase Crashlytics dependency, replace it.
  // When using the BoM, you don't specify versions in Firebase library dependencies
  implementation 'com.google.firebase:firebase-crashlytics'
  implementation 'com.google.firebase:firebase-crashlytics-ndk'
  implementation 'com.google.firebase:firebase-analytics'
}

// …
android {
  // ...
  buildTypes {
      release {
          // Add this extension
          firebaseCrashlytics {
              // 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
          }
      }
  }
}

  dependencies {
      // Declare the dependency for the Firebase Crashlytics NDK library.
      // If you previously declared the Firebase Crashlytics dependency, replace it.
      // When NOT using the BoM, you must specify versions in Firebase library dependencies
      implementation 'com.google.firebase:firebase-crashlytics:18.0.0'
      implementation 'com.google.firebase:firebase-crashlytics-ndk:18.0.0'
      implementation 'com.google.firebase:firebase-analytics:19.0.0'
  }
  

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

dependencies {
  // ...

  // Import the BoM for the Firebase platform
  implementation platform('com.google.firebase:firebase-bom:28.0.1')

  // Declare the dependency for the Firebase Crashlytics NDK library.
  // If you previously declared the Firebase Crashlytics dependency, replace it.
  // When using the BoM, you don't specify versions in Firebase library dependencies
  implementation 'com.google.firebase:firebase-crashlytics-ktx'
  implementation 'com.google.firebase:firebase-crashlytics-ndk'
  implementation 'com.google.firebase:firebase-analytics-ktx'
}

// …
android {
  // ...
  buildTypes {
      release {
          // Add this extension
          firebaseCrashlytics {
              // 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
          }
      }
  }
}

  dependencies {
      // Declare the dependency for the Firebase Crashlytics NDK library.
      // If you previously declared the Firebase Crashlytics dependency, replace it.
      // When NOT using the BoM, you must specify versions in Firebase library dependencies
      implementation 'com.google.firebase:firebase-crashlytics-ktx:18.0.0'
      implementation 'com.google.firebase:firebase-crashlytics-ndk:18.0.0'
      implementation 'com.google.firebase:firebase-analytics-ktx:19.0.0'
  }
  

Required for Crashlytics NDK version 17.3.0: If your app uses targetSdkLevel 30 or above, you must also disable the Pointer Tagging feature in your app by adding the following to your AndroidManifest.xml:

<application android:allowNativeHeapPointerTagging="false">
...
</application>

For more information, read Developer support for Tagged Pointers.

Step 2: Enable native symbol uploading

To produce readable stack traces from NDK crashes, Crashlytics needs to know about the symbols in your native binaries. Our Gradle plugin includes the uploadCrashlyticsSymbolFileBUILD_VARIANT task to automate this process (to access this task, make sure nativeSymbolUploadEnabled is set to true).

For method names to appear in your stack traces, you must explicitly invoke the uploadCrashlyticsSymbolFileBUILD_VARIANT task after each build of your NDK library. For example:

>./gradlew app:assembleBUILD_VARIANT\
           app:uploadCrashlyticsSymbolFileBUILD_VARIANT

The Crashlytics NDK v17.3.0+ and Gradle plugin v2.4.1+ depend on the presence of the GNU build id within the native shared objects. You can verify the presence of this id by running readelf -n on each binary. If the build id is absent, add -Wl,--build-id to your build system's flags to fix the problem.

Step 3 (optional): Upload symbols for external dependencies

Our symbol upload task assumes you are building your native libraries as part of your Gradle build, using standard NDK build tools such as CMake. If you have externally-built native libraries, or are using a customized NDK build process within Gradle, you may need to explicitly specify the path to your unstripped libraries. The firebaseCrashlytics extension provides the property unstrippedNativeLibsDir to do this.

// …
android {
    // ...
    buildTypes {
        release {
            firebaseCrashlytics {
                nativeSymbolUploadEnabled true
                unstrippedNativeLibsDir ‘path/to/unstripped/parent/dir’
            }
        }
    }
}

Our plugin assumes libraries are located in architecture-specific subdirectories under the specified directory. In the following example, both subdirectories x86 and arm64 contain the libraries libfoo.so and libbar.so.

unstrippedNativeLibsDir/
 +- x86/
      |
      +- libfoo.so
      +- libbar.so
 +- arm64/
      |
      +- libfoo.so
      +- libbar.so

If your build system does not adhere to the above structure/naming scheme, manually create this structure on your local disk prior to invoking the uploadCrashlyticsSymbolFileBUILD_VARIANT task.

Step 4 (optional): Customize NDK crash reports

You can optionally include the crashlytics.h header in your C++ code to add metadata to NDK crash reports, such as logs, custom keys, and user IDs. crashlytics.h is available as a header-only C++ library in the Firebase Android SDK GitHub Repository. Read the comments in the header file for instructions on using the NDK C++ APIs.

Step 5: See your crash reports

Verify that Crashlytics is properly reporting NDK crashes by building your app, uploading symbols, and forcing a native crash. You’ll need to restart the app after it crashes for Crashlytics to send the report. You should see the crash in your Firebase console within a few minutes.

Troubleshooting

If you're seeing different stack traces in the Firebase console and in the logcat, refer to the Troubleshooting guide.