IntelliJ remote debugger connects, but breakpoints are not working

Question

I am trying out the Scala web framework Scalatra. According to the docs here, the steps to enable IntelliJ debugging are:

1. Add the usual JDK options for remote debugging: "-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=5005"
2. Create a "Remote" run configuration in Intellij
3. Start up sbt, run jetty:start, and then start the remote debugger

When I do this, SBT prints out:

Listening for transport dt_socket at address: 5005

And IntelliJ prints:

Connected to the target VM, address: 'localhost:5005', transport: 'socket'

However, breakpoints do not seem to be working. When I hit the following endpoint, with a breakpoint at the *:

class AppServlet extends AppStack {
  get("/break-test") {
*   val response = "DONE"
    response
  }
}

The code does not stop at that line, but continues so I get the response DONE back.

I am using Java 1.8.0_111, Scala 2.12, and SBT 0.13.15.

Answer 1

Ah finally, After big struggle ! I found it for me !

I needed to disable forking in build.sbt

 fork in Test := false,

It makes total sense, as it's only the first JVM who would get to be attach to the IDE.

I hope it help someone !

Answer 2

This is what I use for remote debugging:

-agentlib:jdwp=transport=dt_socket,server=y,suspend=n,addres‌​s=5005.

The value you use above in your answer, -Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=5005, is used in the For JDK 1.4.x field.