Flutter: Execution failed for task ‘:app:compileDebugKotlin’

In this post, we’ll be discussing a common issue that developers face while building Flutter applications. The error message “Execution failed for task ‘:app:compileDebugKotlin'” is usually encountered when there’s a problem with the Kotlin version in your build.gradle file or any other Gradle-related issues.

Causes of the Error

The error can be caused by several reasons, but most commonly it’s due to an outdated Kotlin version. This issue can occur even if you’re not directly using Kotlin in your project, as Flutter uses Kotlin for some internal features.

However, other Gradle-related issues like corrupted cache files or mismatched dependencies can also trigger this error. In such cases, deleting the android/.gradle directory and rebuilding the app usually solves the problem.

Solution 1: Upgrade Your Kotlin Version

To solve this issue, you need to go to your build.gradle file in the root of your Android directory. This is where you’ll find the version number for Kotlin.

ext.kotlin_version = '1.5.10'

You can check the latest Kotlin version on the official Kotlin website. Just copy the new version and replace the old one in your build.gradle file.

Solution 2: Delete android/.gradle Directory and Rebuild

Another common solution to this problem is deleting the android/.gradle directory. This usually clears up any corrupted cache files that might be causing the issue.

# Delete the .gradle directory
rm -rf android/.gradle

# Then, run your app in debug mode
flutter run --debug

This should rebuild your app from scratch and update any Gradle-related files. If you’re using a code editor or IDE like Android Studio, this action might take some time.

Conclusion

The “Execution failed for task ‘:app:compileDebugKotlin'” error is usually easy to fix by upgrading your Kotlin version in the build.gradle file or deleting the android/.gradle directory. Both solutions are straightforward and don’t require any complex coding knowledge.