R8 Retrace No Longer Generates Correct Line Numbers? Here’s the Fix!

Now that we’ve identified the potential causes and troubleshooted the issue, let’s move on to the solutions:

Solution 1: Update R8 Configuration

The first solution is to update your R8 configuration files to ensure they’re correct and compatible:

{
  "optimizationLevel": "2",
  "minification": {
    "renameVariables": false
  },
  "debugOptions": {
    "enableLineNumbers": true
  }
}

In this example, we’re setting the optimization level to 2 and disabling variable renaming. We’re also enabling line number generation by setting enableLineNumbers to true.

Solution 2: Update Android Gradle Plugin

If updating the R8 configuration doesn’t work, try updating the Android Gradle Plugin to the latest version:

dependencies {
  classpath 'com.android.tools.build:gradle:4.1.0'
}

In this example, we’re updating the Android Gradle Plugin to version 4.1.0. Make sure to replace the version with the latest one available.

Solution 3: Use Java 8 or Later

If you’re still experiencing issues, ensure you’re using Java 8 or later:

java -version
openjdk 14.0.2 2022-06-08
OpenJDK Runtime Environment (build 14.0.2+12-46)
OpenJDK 64-Bit Server VM (build 14.0.2+12-46, mixed mode, sharing)

In this example, we’re using OpenJDK 14.0.2, which is compatible with R8.

Solution 4: Clean and Rebuild Project

Sometimes, a simple clean and rebuild of your project can resolve the issue:

./gradlew clean
./gradlew build

Run these commands in your terminal to clean and rebuild your project.

Best Practices to Avoid Incorrect Line Numbers

To avoid incorrect line numbers in the future, follow these best practices:

• Regularly Update R8 Configuration**: Ensure your R8 configuration files are up-to-date and compatible with the latest Android Gradle Plugin versions.
• Monitor Source Code Changes**: Keep track of changes in your source code and test your R8 retrace output regularly to catch any issues early.
• Use Compatible Java Versions**: Always use compatible Java versions (Java 8 or later) to ensure R8 functions correctly.