Debugging Gradle Builds

Introduction

• Debugging Gradle builds can be frustrating.
• Video discusses 3 ways to debug Gradle effectively.

Debugging with IntelliJ IDEA

• IntelliJ IDEA is a popular IDE for Java and Gradle development.
• Example: Big error appeared: "Gradle exception unsupported operating system."
  • Steps to Debug:
    1. Open project and locate error.
    2. Set a breakpoint by clicking on the left-hand side of the code.
    3. Open the Gradle panel (right-hand side), select a task, right-click, and hit the debug button.
    4. Execution stops at the breakpoint.
    5. Utilize IDE's debug tools:
       • Step over lines (F8).
       • Check variable values.
       • Browse the stack to identify errors.

Debugging a Plugin with Command Line

• Scenario: Debugging inside a plugin, e.g., com.palantir.docker plugin.
• Steps to Debug:
  1. Run build with a debug flag: gradle w docker -Dorg.gradle.debug=true.
  2. Execution suspends, waiting for a remote debugger.
  3. Open plugin project, navigate to code, and set a breakpoint.
  4. Go to "Run Debug Configurations," add a remote debug configuration on port 5005.
  5. Select the correct module classpath and connect.
  6. Use IDE debug tools to investigate plugin code.

Debugging a Gradle Plugin Test

• Context: Writing tests for Gradle plugins using Gradle Runner.
• Issue: Test fails without stopping at breakpoints.
• Solution:
  1. Use gradle runner to create a temporary build.
  2. Add .withDebug(true) in your test setup.
  3. Run the test in debug mode to pause at breakpoints.

Summary

• Key Flags & Tools:
  • Use -Dorg.gradle.debug=true for remote debugging.
  • Use .withDebug(true) for debugging plugin tests with Gradle Runner.
• IDE Benefits: Access comprehensive debug tools, step over code, and inspect execution flow.

Conclusion

• These methods provide structured approaches to resolving Gradle build issues.
• Encouragement to share tips or ask questions in the comments.

• Closing: Thanks for watching, and look forward to the next episode on Tom Gregory Tech.