Debugging GeasyBPMNEditor doesn't require any specific configuration than another project also running with GWT and Maven.

1. Run GWT in debug mode with maven, it will wait until something happens on port 8000:
2. In Eclipse, create a Remote Java Application configuration (Run > Debug Configurations) . In the right panel, select "Remote Java Application" then click on "New launch configuration" icon (located on the top of the panel). So far, you should have something like this :
   Select the project that you'd like to debug, and don't change the Connection Properties that should be: Host = localhost and Port = 8000 . Click on debug, that should launch GWT Development Mode console . That's it , now Eclipse should go in debug mode when you add Beakpoints in you code, and of course you can run the application in your browser as if it was launched with a mvn gwt:run command.