Unity Android Build Error Fix - DexArchiveMergerException & MultiDex

Identifying the Cause

• Upgraded Unity version from 2022.3.4f1 to 2022.3.19f1.
• Updated Build Machine (Mac Mini) to MacOS Sonoma 14.3.1 and Xcode 15.2.
• An unknown error occurred during remote build for DEV Android via Jenkins.

First Failure Cause and Solution: Enabling MultiDex

User
ERROR:/Users/YOUR_USERNAME/.jenkins/workspace/(DEV)android/Library/Bee/Android/Prj/IL2CPP/Gradle/unityLibrary/build/.transforms/f5f2117adcaee1eb1097391e7bb3025e/transformed/classes/classes.dex: D8: Type com.google.firebase.MessagingUnityPlayerActivity is defined multiple times: ...
com.android.builder.dexing.DexArchiveMergerException: Error while merging dex archives: 
Type com.google.firebase.MessagingUnityPlayerActivity is defined multiple times: ...

• It seems the cause was a duplicate class definition: com.google.firebase.MessagingUnityPlayerActivity. Specifically, classes defined more than once cause conflicts in two dex archives.
• To resolve this, enabling MultiDex was required. Similar issues have been reported in Unity forums and discussions.
• Although some threads date back to 2014 or 2019, I decided to proceed with enabling the MultiDex option as I needed to try every possible solution to fix this build.

Reference: StackOverflow Answer

1. Unity Forum MultiDex

2. Unity Discussion MultiDex

• According to the forums and discussions, setting multiDexEnabled true resolves the DexArchiveMergerException.
• I found the mainTemplate.gradle file inside the Plugin - Android folder and added the following code:

android {
    ...

    defaultConfig {
        ...
        multiDexEnabled true
    }

    ...
}

• Note: In the image below, DISABLED is appended to the filename, suggesting it might not be included in the build or is disabled. It’s a mystery why it affects the build…

Result: Enabling MultiDex resolved this error. However, another error occurred…

Second Failure Cause and Solution: Execution failed for task ‘:launcher:mergeDexRelease’ & gradle build failed

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':launcher:mergeDexRelease'.
> A failure occurred while executing com.android.build.gradle.internal.tasks.DexMergingTaskDelegate
   > There was a failure while executing work items
      > A failure occurred while executing com.android.build.gradle.internal.tasks.DexMergingWorkAction
         > com.android.builder.dexing.DexArchiveMergerException: Error while merging dex archives: 
           Type com.google.firebase.MessagingUnityPlayerActivity is defined multiple times: 

• The above log appeared during the Jenkins build. I suspect this error occurred due to enabling MultiDex.

Reference: app:mergeDexRelease Error

Reference: Gradle Build Failed Fix Blog

• The referenced blog was also outdated, so the settings environment was quite different.
• There is a checkbox in ProjectSettings - Android - Publishing Settings - Minify - Release. Enabling this checkbox solves it.

• However, be warned that like “Strip Engine Code,” this might exclude specific binary files from the build. No one knows what issues that might cause…

• Update 2024.3.6: It says it deletes or excludes Java Code binary files, and it actually did… Adjust was not included in the build, so I had to disable this option again.

• Warning text…

Result: Enabling that option in Project Settings solved it!! But… yet another error occurred… (This part was due to internal project code issues)

Third Failure Cause and Solution: Native Crash Reporting (Caused by Internal Project Code)

Filename: Assets/Editor/Build/ShaderCleanup.cs Line: 68


=================================================================
	Native Crash Reporting
=================================================================
Got a segv while executing native code. This usually indicates
a fatal error in the mono runtime or one of the native libraries 
used by your application.
=================================================================

=================================================================
	Native stacktrace:
=================================================================

• This code removes unnecessary shaders during build post-processing… Strangely, it had no issues before but started crashing now. ImportAsset seems to be the problem.
• Since it was a Native Crash, I couldn’t see detailed error logs… It is presumed that it tried to remove a non-existent shader.

public void OnPreprocessBuild(BuildReport report)
{
    // Logic to identify and disable unused shaders or assets

    // Example: Find and disable all unused shaders
    DeactivateUnusedShaders();
}

 private void DeactivateUnusedShaders()
{
  ...

     AssetDatabase.ImportAsset(AssetDatabase.GUIDToAssetPath(shaderPath), ImportAssetOptions.ForceUpdate);

  ...
}

• Solved by commenting out this code and proceeding with the build…