JDK source files not opening in the editor when stepping to JDK classes (unknown sources in the call stack).  #1437

I am using VS code with WSL2 remote connection.
It's a maven project and its using openJDK 8.

When I launch the java debugger, I can debug into maven dependencies, but when I try to debug into JDK class files, I get "unknown source". I have checked the openJDK 8 installation and the src.zip file is there $JAVA_HOME/src.zip

I have JAVA_HOME set in my env in WSL to point to the openJDK 8 version.
I also tried setting "java.jdt.ls.java.home" in the settings.json file but VS code complains the java version does not meet minimum requirements.

Is there a way to configure the java debugger to use the openJDK 8 src.zip file with this setup.

Environment

• Operating System: Windows 10 Enterprise
• JDK version: openjdk version "1.8.0_292"
• Visual Studio Code version:
  Version: 1.86.0 (user setup)
  Commit: 05047486b6df5eb8d44b2ecd70ea3bdf775fd937
  Date: 2024-01-31T10:28:19.990Z
  Electron: 27.2.3
  ElectronBuildId: 26495564
  Chromium: 118.0.5993.159
  Node.js: 18.17.1
  V8: 11.8.172.18-electron.0
  OS: Windows_NT x64 10.0.19044
• Java extension version: v0.25.15
• Java Debugger extension version: v0.56.0

Steps To Reproduce

1. Attach to remote WSL maven project.
2. WSL using Apache Maven 3.6.3, with openJDK 8.
3. Create a simple program with JDK classes.
4. Debug the program and try to step into the JDK classes.
5. Unknown source is indicated when debugging into the JDK classes.

The program to re-produce is as simple as the following:

public static void main(String[] args) {
String test = new String("test");
LOGGER.info("{}", test);
}

Set a breakpoint on new String and try to step into the constructor.
Note, in the java projects view, I can see the JRE system library and browse the JDK code with no issues.

I can even put a breakpoint into the JDK source code (String constructor in this case), and run to that breakpoint, but the source code does not pop up in the editor, I see unknown source in the call stack.

Current Result

Unknown source for JDK classes when trying to debug.

Expected Result

Debugger can step into source code for JDK classes.

Additional Informations