Missing copyFlutterAssetsDebug task dependency

[markushi]

Description

Flutter registers it's own copyAssets task, which get's wired up with the mergeAssets task here: https://github.com/flutter/flutter/blob/6ce591f7ea3ba827d9340ce03f7d8e3a37ebb03a/packages/flutter_tools/gradle/src/main/groovy/flutter.groovy#L1295-L1298

Our plugin on the other hand uses assets transformer to inject the properties file:

sentry-android-gradle-plugin/plugin-build/src/main/kotlin/io/sentry/android/gradle/AndroidComponentsConfig.kt

Lines 124 to 139 in 6d1c33d

	// we can't hook into asset generation, nor manifest merging, as all those tasks
	// are dependencies of the compilation / minification task
	// and as our ProGuard UUID depends on minification itself; creating a
	// circular dependency
	// instead, we transform all assets and inject the properties file
	sentryVariant?.assetsWiredWithDirectories(
	InjectSentryMetaPropertiesIntoAssetsTask.register(
	project,
	extension,
	sentryTelemetryProvider,
	tasksGeneratingProperties,
	variant.name.capitalized
	),
	InjectSentryMetaPropertiesIntoAssetsTask::inputDir,
	InjectSentryMetaPropertiesIntoAssetsTask::outputDir
	)

The transformer is used to avoid any tasks dependencies, as copyFlutterAssets is hooked up in a way that it depends on the minify task, which is a required input for our task, leading to circular dependencies, see this related issue for more details: getsentry/sentry-react-native#3644

Steps to reproduce:

1. setup a blank flutter app
2. setup sentry
3. setup assets for the flutter app via pubspec.yaml

  assets:
    - some/random/file.png

4. Try to build the app, it fails with the following error message:

FAILURE: Build failed with an exception.

* What went wrong:
A problem was found with the configuration of task ':app:injectSentryDebugMetaPropertiesIntoAssetsDebug' (type 'InjectSentryMetaPropertiesIntoAssetsTask').
  - Gradle detected a problem with the following location: '<app>/build/app/intermediates/assets/debug/mergeDebugAssets'.
    
    Reason: Task ':app:injectSentryDebugMetaPropertiesIntoAssetsDebug' uses this output of task ':app:copyFlutterAssetsDebug' without declaring an explicit or implicit dependency. This can lead to incorrect results being produced, depending on what order the tasks are executed.
    
    Possible solutions:
      1. Declare task ':app:copyFlutterAssetsDebug' as an input of ':app:injectSentryDebugMetaPropertiesIntoAssetsDebug'.
      5. Declare an explicit dependency on ':app:copyFlutterAssetsDebug' from ':app:injectSentryDebugMetaPropertiesIntoAssetsDebug' using Task#dependsOn.
      6. Declare an explicit dependency on ':app:copyFlutterAssetsDebug' from ':app:injectSentryDebugMetaPropertiesIntoAssetsDebug' using Task#mustRunAfter.
    
    For more information, please refer to https://docs.gradle.org/8.2/userguide/validation_problems.html#implicit_dependency in the Gradle documentation.

[markushi]

Quick update: We're still looking into this. If you're facing this issue a downgrade to version 4.2.0 might be a viable alternative.