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Unity Engine

Android symbols

Generate symbols to help you debug a built Android application.
Read time 6 minutesLast updated 10 days ago
To help you debug your application, Unity can generate a package that contains symbol files with debug metadata for native Unity libraries. Symbol files contain an executable file section called symbol table (
.symtab
) that translates active memory addresses into information you can use, like a method name. The translation process is called symbolication. You can upload a symbols package to the Google Play Console to see a human-readable stack trace on the Android Vitals dashboard.
For more information about executable file (ELF) section, refer to Wikipedia.
Unity generates symbol files for the following libraries:
  • libunity
    : Unity’s engine code:
    • If Strip Engine Code property is disabled, the symbol file is precompiled.
    • If Strip Engine Code property is enabled, Unity compiles the symbol file during build process.
  • libil2cpp
    : Contains C# scripts:
    • If you don't export your project, Unity compiles the symbol file during build process.
    • If you export your project, Gradle compiles the symbol file.
Gradle generates symbol files for any additional shared libraries by stripping the 
.symtab
and 
.debug*
executable file sections from the shared libraries. If a shared library doesn't contain these sections, Gradle will not generate a symbol file for it.
Depending upon your application build format, Unity generates symbol files in two ways :
  • As a zip file that can be generated for both 
    apk
    or 
    aab
    .
  • Directly embeds symbol files in the 
    aab
    . Unity doesn't embed symbol files into an 
    apk
    .
Use UserBuildSettings.DebugSymbols.format API to set the format of the symbol package.

Types of symbol files

Unity uses debugSymbolLevel property of Gradle to generate symbol files. There are two types of symbol files:
  • Public: A small file that contains a symbol table section. For more information, refer to Public symbols.
  • Debugging: Contains everything that a public symbol file contains along with full debugging information that you can use for more in-depth debugging. For more information, refer to Debugging symbols.
Use UserBuildSettings.DebugSymbols.level to generate the required type of symbol file.
Note
By default, Gradle generates symbol files with 
.so.sym
or 
.so.dbg
extensions. Some digital distribution services don't recognize these extensions and require files with 
.so
extension. In such cases, use Unity.Android.Types.DebugSymbolFormat.LegacyExtensions API to create symbol files with 
.so
extension.
UserBuildSettings.DebugSymbols.format = DebugSymbolFormat.IncludeInBundle | DebugSymbolFormat.Zip | DebugSymbolFormat.LegacyExtensions;

Public symbols

A public symbols file contains information that resolves function addresses to human-readable strings. These files don't contain debugging information. This makes public symbol files smaller than debugging symbols files.

Debugging symbols

A debugging symbols file contains full debugging information and a symbol table section. Use it to:
  • Resolve stack traces and to debug applications that you have source code available for.
  • Attach a native debugger to the application and debug the code.
Note
If debugging symbols aren't available, Unity places a public symbols file in your project at build time. For the 
libunity
library, debugging symbols aren't available and Unity always generates public files.

Custom symbols

You can instruct Unity to include additional symbol files. This is useful if you use shared libraries and want your local debugger, and Google Play, to resolve the shared library stack traces if the application crashes.
To make Unity include a custom symbols file:
  1. In the Project window, select a plug-in that has a 
    .so
    file extension.
  2. In the Inspector, find the Platform settings section.
  3. Set CPU to the CPU architecture that the symbols file is compatible with.
  4. Set Shared Library Type to Symbol.
Whenever Unity generates a symbols package, it adds the additional symbol files to the symbols package.
Important
If you set the Shared Library Type to Executable and the shared library contains the 
.symtab
and 
.debug*
executable file sections, Gradle generates a symbol file that overwrites your custom symbol file.
If you want to make Unity include a custom symbols file from a C# script, the UnityEditor.Android namespace includes the following APIs to set the CPU and Shared Library Type respectively:
Note
The symbols file name must match the name of the shared library that the symbols file is for. For example, if a shared library is called mylibrary.so, the symbols file must also be named mylibrary.so. To avoid file name collisions, the symbols file and the shared library must be in separate directories.
Important
Ensure the symbols file is up to date and compatible with the shared library that contains the executable code. If you don't, your local debugger and Google Play will fail to resolve stack traces for code in the shared library.

Custom plug-in in the Inspector.

Generating a symbols package

There are two ways to enable symbols package generation for your application:
To enable symbols package generation through the Build Profiles window:
  1. Open the Build Profiles window (menu: File > Build Profiles).
  2. From the list of platforms in the Platforms panel, select Android or create a build profile for the Android platform.
  3. Set Debug Symbols to one of the following:
  4. Set Symbols output options to .zip.
After you enable symbols package generation, building your project generates a 
.zip
file that contains a symbol file for the 
libunity
library. If you set your scripting backend to
IL2CPP

?

, the 
.zip
also contains a symbol file for the 
libil2cpp
library. Unity places this symbols package within the output directory. The name of the symbols package file is in this format: 
<appbuildfilename>-<version>-v<bundle version code>-IL2CPP.symbols.zip
. For example, 
MyApp-0.1-v100-IL2CPP.symbols.zip
where 
MyApp
is the name of your application build file, 
0.1
is the version, and 
100
is the bundle version code. The version and bundle version code are set in the Android Player settings.
If you enable Export Project in the Android build settings, Unity doesn't build the project. Instead, it exports the project for Android Studio, generates a symbol file for 
libunity
, and places it within 
unityLibrary/symbols/<architecture>/
in the output directory. When you build your exported project from Android Studio, Gradle generates the 
libil2cpp
symbol file and places it within the 
unityLibrary/symbols/<architecture>/
directory alongside the 
libunity
symbol file.

Using symbols in the Google Play console

Embedded symbols

If you're producing an Android App bundle (aab), you can embed symbols directly into an 
aab
and upload it to Google Play.
Note
Unity doesn't embed symbols into an 
apk
. In this case, you must upload a zip file with symbols separately.
UserBuildSettings.DebugSymbols.level = DebugSymbolLevel.SymbolTable;UserBuildSettings.DebugSymbols.format = DebugSymbolFormat.IncludeInBundle;

Zipped symbols

To produce a zipped symbols package, use the following code:
UserBuildSettings.DebugSymbols.level = DebugSymbolLevel.SymbolTable;UserBuildSettings.DebugSymbols.format = DebugSymbolFormat.Zip | DebugSymbolFormat.LegacyExtensions;
After you upload your application to Google Play, you can upload a public symbols zip package. For information on how to do this, refer to Google's documentation: Deobfuscate or symbolicate crash stack traces.
Note
Google Play doesn't symbolicate crashes that your application received before you uploaded the symbols package.