Android AGP 9: Unresolved reference SnapshotSender / PostHogFlutterSurveysDelegate

[jamalalayeq]

posthog_flutter 5.42.1 and 5.47.0 fail to compile on Android Gradle Plugin 9.2 when android.builtInKotlin=false (the Flutter migrator default).

e: PosthogFlutterPlugin.kt:154:34 Unresolved reference 'SnapshotSender'.
e: PosthogFlutterPlugin.kt:158:41 Unresolved reference 'PostHogFlutterSurveysDelegate'.
e: PosthogFlutterPlugin.kt:651:40 Unresolved reference 'PostHogFlutterSurveysDelegate'.
e: PosthogFlutterPlugin.kt:2202:33 Unresolved reference 'handleSurveyAction'.

SnapshotSender, PostHogFlutterSurveysDelegate, and handleSurveyAction are all in android/src/main/kotlin/com/posthog/flutter/, same package as PosthogFlutterPlugin.kt. They are unresolved because android/build.gradle still does:

sourceSets {
    main.java.srcDirs += 'src/main/kotlin'
}

AGP 9 does not support adding Kotlin sources to the Java source set (migration guide). Those .kt files are then compiled apart from the Kotlin source set, so sibling classes are invisible. 5.47.0 still has this block.

Please stop adding src/main/kotlin to java.srcDirs. src/main/kotlin is already the Kotlin source directory for both KGP and built-in Kotlin.

Toolchain: AGP 9.2.0, Kotlin 2.2.20, android.builtInKotlin=false, android.newDsl=false.

[turnipdabeets]

Hey @jamalalayeq, thanks for the report!

Unfortunately I couldn't reproduce this. A fresh flutter create app with posthog_flutter 5.42.1 or 5.47.0 builds fine (debug and release) on AGP 9.2.0, Kotlin 2.2.20, Gradle 9.4.1, builtInKotlin=false and newDsl=false. It also builds with builtInKotlin=true, with JDK 17 or 21, after an AGP 8→9 upgrade without a clean build, and with the Kotlin plugin declared in different places.

A couple of notes:

• The log you pasted is from 5.42.1 (e.g. SnapshotSender is at line 154 there, but line 155 in 5.47.0), so a 5.47.0 log would help.
• The migration guide's "not supported" note is for built-in Kotlin, and you mentioned android.builtInKotlin=false, which turns it off.

Could you share:

1. flutter doctor -v output, and ./gradlew --version run from android/
2. Whether it still fails after flutter clean and deleting android/.gradle and android/.kotlin
3. android/gradle.properties, and the relevant parts of your settings.gradle(.kts), root build.gradle(.kts) and app/build.gradle(.kts) (any subprojects {}, sourceSets or kotlin {} blocks). Please remove signing configs, keys and private repo URLs first.
4. Your other plugins in pubspec.yaml
5. How you build (CLI or Android Studio, debug or release, any flavors), and a full log with 5.47.0: run flutter build apk --debug -v > build-log.txt 2>&1 and attach build-log.txt here
6. If possible, a minimal repro: a new flutter create app with only posthog_flutter added

On Windows, also mention whether your project and your pub cache are on different drives. If you'd rather not post these publicly, email them to anna.g [at] posthog dot com.

I'd like to reproduce the failure before changing the srcDirs line.

Cc @ioannisj in case I'm missing something.