Java remote attach to debug not hitting breakpoints.

[jkryanchou]

[provide a description of the issue]

Environment

• Operating System: MacOSX Mojave 10.14.6
• JDK version: 1.8.0_121
• Visual Studio Code version: 1.14.1
• Java extension version: 0.8.1
• Java Debugger extension version: 0.24.0

Steps To Reproduce

1. [step 1] Set remote debug configuration

    {
           "type": "java",
           "name": "Debug (Attach) - Remote",
           "request": "attach",
           "hostName": "192.168.1.1",
           "timeout": 30000,
           "port": 8000,
           "projectName": "service"
       },
   

2. [step 2] Run and Debug remote, and it shows that warning message, and not hitting the breakpoints set below.

   [Warn - 11:25:04 AM] 2020-2-3 11:25:04 [Warn] The debugger and the debuggee are running in different versions of JVMs. You could see wrong source mapping results.
   Debugger JVM version: 1.8.0_121
   Debuggee JVM version: 1.8.0_102

[attach a sample project reproducing the error]
attach logs

Current Result

Not hitting the breakpoints.

Expected Result

Hit the breakpoints and could view the variables.

Additional Informations

I used the IDEA remote attach through the commands, and it works without problem. I wonder if any differences between IDEA and VSCode-java-debug remote attach commands?

• IDEA Remote debug options
  

• VSCode Java Debug remote attach configuration

[jkryanchou]

Anyone could help me out with this issue?

[akaroml]

@jkryanchou, thanks for reaching out.

The remote capability of VS Code is different from remote debugging in IntelliJ. We would love to help but we are not able to reproduce the issue based on the materials provided in this thread.

Could you please share the project with us?

[jkryanchou]

The repository was private. Is there any other data I could provide to help me out with this issue?

[testforstephen]

@jkryanchou, could you share the command line arguments to launch your remote service?

[jkryanchou]

@testforstephen How could I print out the command line arguments which to launch the remote service In VSCode? Or you mean the launch.json configuration?

[testforstephen]

To debug a remote Java program, it has two steps:
Step 1: Start the application in debugging mode

java -agentlib:jdwp=transport=dt_socket,server=y,suspend=y,address=<debug-port> -cp <ClassPath> <ClassName>

Step 2: Configuration launch.json to attach to the application.

Currently if you're using attach debugging in VS Code, you must manually launch your service at first. Could you tell me the approach to launch your service?

[jkryanchou]

@testforstephen Here are the agentlib commandline args:

java -agentlib:jdwp=transport=dt_socket,address=8000,server=y,suspend=n

[testforstephen]

In the args, suspend=n, this means your application is started not in suspend mode. The application will start execution immediately, and no need to wait for a debugger to connect it. This is why you don't see hitting breakpoints, because your program may have executed the breakpoint code before the debugger ready.

To solve your program, you need set suspend=y, then the JVM starts in suspended mode and stays suspended until a debugger attaches to it.

[jkryanchou]

@testforstephen OK, Thanks a lot. I will try it later. If any other issue exists . I would reply on this issue.

[jkryanchou]

@testforstephen I have changed the suspend=y args. while it works as before and still couldn't hit the breakpoint. I guess it was something wrong with my network to the remote java agent.

[lherman-cs]

I'm also having a similar issue