How to debug tests ran from sbt

Question

Tests run from sbt don't show an stacktrace when an exception happens, so I would like to connect to sbt from a debugger to debug the tests. What is an easy way of doing that?

Answer 1

Using the sbt deb/rpm provided by typesafe, this works:

sbt -jvm-debug 8000

Answer 2

You can create a separate sbt launcher with the java jdwp args, i.e. -agentlib:jdwp=transport=dt_socket,suspend=y,server=y,address=10000

From here, you can connect your debugger to port 10,000.